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  • 1.
    Ahmadzadeh, Farzaneh
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Application of multi regressive linear model and neural network for wear prediction of grinding mill liners2013Inngår i: International Journal of Advanced Computer Sciences and Applications, ISSN 2158-107X, E-ISSN 2156-5570, Vol. 4, nr 5, s. 53-58Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The liner of an ore grinding mill is a critical component in the grinding process, necessary for both high metal recovery and shell protection. From an economic point of view, it is important to keep mill liners in operation as long as possible, minimising the downtime for maintenance or repair. Therefore, predicting their wear is crucial. This paper tests different methods of predicting wear in the context of remaining height and remaining life of the liners. The key concern is to make decisions on replacement and maintenance without stopping the mill for extra inspection as this leads to financial savings. The paper applies linear multiple regression and artificial neural networks (ANN) techniques to determine the most suitable methodology for predicting wear. The advantages of the ANN model over the traditional approach of multiple regression analysis include its high accuracy.

  • 2.
    Ahmadzadeh, Farzaneh
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Remaining useful life estimation: Review2014Inngår i: International Journal of Systems Assurance Engineering and Management, ISSN 0975-6809, E-ISSN 0976-4348, Vol. 5, nr 4, s. 461-474Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper reviews the recent modelling developments in estimating the remaining useful life (RUL) of industrial systems. The RUL estimation models are categorized into experimental, data driven, physics based and hybrid approaches. The paper reviews some typical approaches and discusses their advantages and disadvantages. According to the literature, the selection of the best model depends on the level of accuracy and availability of data. In cases of quick estimations which are less accurate, the data driven method is preferred, while the physics based approach is applied when the accuracy of estimation is important.

  • 3.
    Ahmadzadeh, Farzaneh
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Remaining useful life prediction of grinding mill liners using an artificial neural network2013Inngår i: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 53, s. 1-8Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Knowing the remaining useful life of grinding mill liners would greatly facilitate maintenance decisions. Now, a mill must be stopped periodically so that the maintenance engineer can enter, measure the liners’ wear, and make the appropriate maintenance decision. As mill stoppage leads to heavy production losses, the main aim of this study is to develop a method which predicts the remaining useful life of the liners, without needing to stop the mill. Because of the proven ability of artificial neural networks (ANNs) to recognize complex relationships between input and output variables, as well as its adaptive and parallel information-processing structure, an ANN has been designed based on the various process parameters which influence wear of the liners. The process parameters were considered as inputs while remaining height and remaining life of the liners were outputs. The results show remarkably high degree of correlation between the input and output variables. The performance of the neural network model is very consistent for data used for training (seen) and testing (unseen).

  • 4.
    Ahmadzadeh, Farzaneh
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Strömberg, Thomas
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Matematiska vetenskaper.
    Multivariate process parameter change identification by neural network2013Inngår i: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 69, nr 9-12, s. 2261-2268Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Whenever there is an out-of-control signal in process parameter control charts, maintenance engineers try to diagnose the cause near the time of the signal which is not always lead to prompt identification of the source(s) of the out-of-control condition and this in some cases yields to extremely high monetary loses for manufacture owner. This paper applies multivariate exponentially weighted moving average (MEWMA) control charts and neural networks to make the signal identification more effective. The simulation of this procedure shows that this new control chart can be very effective in detecting the actual change point for all process dimension and all shift magnitudes considered. This methodology can be used in manufacturing and process industries to predict change points and expedite the search for failure causing parameters, resulting in improved quality at reduced overall cost. This research shows development of MEWMA by usage of neural network for identifying the step change point and the variable responsible for the change in the process mean vector.

  • 5.
    Al-Chalabi, Hussan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Al-Douri, Yamur
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Time Series Forecasting using ARIMA Model: A Case Study of Mining Face Drilling Rig2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This study implements an AutoregressiveIntegrated Moving Average (ARIMA) model to forecast totalcost of a face drilling rig used in the Swedish mining industry.The ARIMA model shows different forecasting abilities usingdifferent values of ARIMA parameters (p, d, q). However,better estimation for the ARIMA parameters is required foraccurate forecasting. Artificial intelligence, such as multiobjective genetic algorithm based on the ARIMA model, couldprovide other possibilities for estimating the parameters. Timeseries forecasting is widely used for production control,production planning, optimizing industrial processes andeconomic planning. Therefore, the forecasted total cost data ofthe face drilling rig can be used for life cycle cost analysis toestimate the optimal replacement time of this rig.

  • 6.
    Al-Douri, Yamur K.
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Hamodi, Hussan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Time Series Forecasting using a Two-level Multi-objective Genetic Algorithm: A case study of cost data for tunnel fans2018Inngår i: Algorithms, ISSN 1999-4893, Vol. 11, nr 8, artikkel-id 123Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The aim of this study is to develop a novel two-level multi-objective genetic algorithm (GA) to optimize time series forecasting data for fans used in road tunnels by the Swedish Transport Administration (Trafikverket). The first level is for the process of forecasting time series cost data, while the second level evaluates the forecasting. The first level implements either a multi-objective GA based on the ARIMA model or based on the dynamic regression model. The second level utilises a multi-objective GA based on different forecasting error rates to identify a proper forecasting. Our method is compared with the ARIMA model only. The results show the drawbacks of time series forecasting using the ARIMA model. In addition, the results of the two-level model show the drawbacks of forecasting using a multi-objective GA based on the dynamic regression model. A multi-objective GA based on the ARIMA model produces better forecasting results. In the second level, five forecasting accuracy functions help in selecting the best forecasting. Selecting a proper methodology for forecasting is based on the averages of the forecasted data, the historical data, the actual data and the polynomial trends. The forecasted data can be used for life cycle cost (LCC) analysis.

  • 7.
    Anandika, Rayendra
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Stenström, Christer
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Non-destructive measurement of artificial near-surface cracks for railhead inspection2019Inngår i: Insight (Northampton), ISSN 1354-2575, E-ISSN 1754-4904, Vol. 61, nr 7, s. 373-379Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper delivers a study involving the inspection of artificial surface cracks with depths ranging from 0.25-2.5 mm from the surface and with a crack angle of 30°, which is a typical angle for surface cracks in railheads. The inspections were conducted using three different techniques: phased array ultrasonics, single-element ultrasonics and alternating current potential drop (ACPD). For the ultrasonic techniques, the study focused on employing either longitudinal or shear wave signals. In the railway industry, shallow surface cracks in railheads are caused by rolling contact fatigue (RCF). In this study, artificial defects were made, allowing the authors to explore the extent to which the ultrasonic measurement techniques can detect such defects. The negative effect of a dead zone near to the surface in the ultrasonic tests was reduced by using a wedge attachment. A discussion on the extent to which the techniques can be used in field tests was also provided. The most important result is that shallow cracks ranging from 0.25-2.5 mm were successfully characterised with acceptable accuracy. The 2.5 mm-deep crack can be measured with an accuracy of 0.8% using a 20 MHz single-element probe and with an accuracy of 3.5% using a 5 MHz phased array (64 elements, 0.6 mm pitch). The characterisations were performed using a filtering method that was developed in this study.

    1675605

  • 8.
    Arasteh khouy, Iman
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Larsson-Kråik, Per-Olof
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Nissen, Arne
    Trafikverket.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Geometrical degradation of railway turnouts: a case study from a Swedish heavy haul railroad2014Inngår i: Proceedings of the Institution of mechanical engineers. Part F, journal of rail and rapid transit, ISSN 0954-4097, E-ISSN 2041-3017, Vol. 228, nr 6, s. 611-619Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Turnouts are critical components of track systems in terms of safety, operation and maintenance. Each year, a considerable part of the maintenance budget is spent on their inspection, maintenance and renewal. Applying a cost-effective maintenance strategy helps to achieve the best performance at the lowest possible cost. In Sweden, the geometry of turnouts is inspected at predefined time intervals using the STRIX / IMV 100 track measurement car. This study uses time series for the measured longitudinal level of turnouts on the Iron Ore Line (Malmbanan) in northern Sweden. Two different approaches are applied to analyse the geometrical degradation of turnouts due to dynamic forces generated by train traffic. In the first approach, the recorded measurements are adjusted at the crossing point and then the relative geometrical degradation of turnouts is evaluated by using two defined parameters, the absolute residual area and the maximum settlement, In the second approach, various geometry parameters are defined to estimate the degradation in each measurement separately. The growth rate of the longitudinal level degradation as a function of million gross tonnes / time is evaluated. The proposed methods are based on characterisation of the individual track measurements. The results facilitate correct decision-making in the maintenance process through understanding the degradation rate and defining the optimal maintenance thresholds for the planning process. In the long run, this can lead to a cost-effective maintenance strategy with optimised inspection and maintenance intervals.

  • 9.
    Berg, Sven
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Jungmar, Ulf
    Bodycote Materials Testing AB, Linköping.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Vähäoja, Pekka
    Department of Mechanical Engineering, University of Oulu.
    Investigation of the measurement precision of oil analysis instruments, using fully formulated oils: Part 1: Spectroscopic instruments2011Inngår i: Industrial Lubrication and Tribology, ISSN 0036-8792, E-ISSN 1758-5775, Vol. 63, nr 6, s. 404-411Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose - The aim of this study is to determine the variation of the different oil analysis instruments in terms of standard deviation and CV-values, when measuring samples of fully formulated hydraulic and gear oils taken from working systems. Design/methodology/approach - In this investigation, two different spectrometric techniques, inductively coupled plasma-optical emission spectrometers (ICP-OES) and rotating disk electrode-optical emission spectrometers (RDE-OES), have been studied to determine the instruments' precision of measurement and ability to measure the absolute level of contamination. The study was based on a series of measurements using artificial contamination mixed with oil. Findings - The ICP has better precision of measurement of the two instruments, but cannot predict the absolute values of contamination when oil samples are only treated by organic solvent dilution if the samples include large or dense particles. It is therefore not too good, with the sample pre-treatment method used, at detecting wear processes that produce dense/large particles, such as pitting failure. For instance, microwave-assisted acid digestion could be used for sample pre-treating to obtain accurate results in that case. It should, however, be able to detect wear mechanisms that produce small particles such as abrasive wear in any case. The ICP has a repeatability value of r=3 percent and a reproducibility value of R=12 percent for contamination levels of between 50 and 400 ppm and r=0.6 and R=2 ppm, respectively, at values below 50 ppm. The RDE cannot predict the absolute value of contamination if this includes large or dense particles if proper sample pre-treatment is not used. It is therefore not good at detecting wear mechanisms that produces dense/large particles (if the oil samples are not pre-treated properly) such as pitting but should be able to detect abrasive wear and similar processes that produce small particles in any case. The RDE's precision of measurement is not as good as the ICP, with a reproducibility variation of R=r=25 percent for contamination levels between 20 and 500 ppm and R=r=6 ppm for contamination level below 20 ppm. Research limitations/implications - Only the effects from lubricating oils are studied. Practical implications - This study will significantly increase the industrial knowledge concerning measurement precision in particle contamination measurement systems. Originality/value - No similar study is found

  • 10.
    Berg, Sven
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Jungmar, Ulf
    Bodycote Materials Testing AB, Linköping.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Vähäoja, Pekka
    Department of Mechanical Engineering, University of Oulu.
    Investigation of the measurement precision of oil analysis instruments, using fully formulated oils: Part 2: Contamination-measuring instruments2011Inngår i: Industrial Lubrication and Tribology, ISSN 0036-8792, E-ISSN 1758-5775, Vol. 63, nr 6, s. 412-419Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose - The aim of this study is to determine the variation of the different oil analysis instruments in terms of standard deviation and CV-values, when measuring samples of fully formulated hydraulic and gear oils taken from working systems. Design/methodology/approach - In this investigation two different spectrometric techniques, ICP-OES and RDE-OES, have been studied to determine the instruments' precision of measurement and ability to measure the absolute level of contamination. Findings - The ICP has better precision of measurement of the two instruments, but cannot predict the absolute values of contamination when oil samples are only treated by organic solvent dilution if the samples include large or dense particles. It is therefore not too good, with the sample pre-treatment method used, at detecting wear processes that produce dense/large particles, such as pitting failure. For instance, microwave-assisted acid digestion could be used for sample pre-treating to obtain accurate results in that case. It should, however, be able to detect wear mechanisms that produce small particles such as abrasive wear in any case: the ICP has a repeatability value of ITr/IT=3 per cent and a reproducibility value of ITR/IT=12 per cent for contamination levels of between 50-400 PPM and ITr/IT=0.6 PPM and ITR/IT=2 PPM, respectively, at values below 50 PPM; the RDE cannot predict the absolute value of contamination if this includes large or dense particles if proper sample pre-treatment is not used. It is therefore not good at detecting wear mechanisms that produce dense/large particles (if the oil samples are not pre-treated properly) such as pitting but should be able to detect abrasive wear and similar processes that produce small particles in any case; the RDE's precision of measurement is not as good as the ICP, with a reproducibility variation of ITR/IT=ITr/IT=25 per cent for contamination levels between 20-500 PPM and ITR/IT=ITr/IT=6 PPM for contamination level below 20 PPM. Research limitations/implications - Measuring only on fully formulated oils from hydraulic and gear systems. Practical implications - The study will be of significant support regarding industrial interpretation of measurement results from the most common oil particle measurement methods. Originality/value - No other similar studies are known

  • 11.
    Berg, Sven
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Rheological properties of contaminated oil2000Inngår i: Proceedings of the International Tribology Conference: ITC Nagasaki 2000 ; October 29 - November 2, 2000, Tokyo: Japan Society of Tribologists , 2000, s. 1239-1243Konferansepaper (Fagfellevurdert)
  • 12.
    Dandotiya, Rajiv
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Economic model for maintenance decision: a case study for mill liners2012Inngår i: Journal of Quality in Maintenance Engineering, ISSN 1355-2511, E-ISSN 1758-7832, Vol. 18, nr 1, s. 79-97Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose – Wear life of mill liners is an important parameter concerning maintenance decision for mill liners. Variations in process parameters such as different ore properties due to the use of multiple ore types influences the wear life of mill liners whereas random order of processing, processing time and monetary value of different ore types leads to variation in mill profitability. The purpose of the present paper is to develop an economic decision model considering the variations in process parameters and maintenance parameters for making more cost effective maintenance decisions. Methodology/approach – Correlation studies, experimental results and experience of industry experts are used for wear life modeling whereas simulation is used for maximizing mill profit to develop economic decision model. The weighting approach and simulation have been considered to emphasize the contribution of parameters such as ore value and processing time of a specific ore type to a final result. Findings – This study resulted in developing an economic decision support model for mill liner replacement considering the influence of the variation in the process parameters and its affect on maintenance decisions. This study identified the various important process and maintenance parameters and described the influence of variations in the process parameters on decisions model. The results obtained from the model show that an optimum maintenance policy can only not reduce the maintenance cost, but also affect the process performance, which leads to significant improvement in the savings of the ore dressing mill. Originality and Value – The developed model considers the economic influence of ore properties, variation in process parameters and proposed an approach for considering these parameters in decision making which enhance its value in terms of increased mill profit. Practical implications – The proposed economic decision model is practically feasible and can be implemented within the ore dressing mill industries. Using the model, the cost effective maintenance decision can increase the profit of the organization significantly. Paper type – Case study Keywords: Economic model; Replacement decision; Mill liners; Ore properties; Optimization; Process parameters

  • 13.
    Dandotiya, Rajiv
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Parida, Aditya
    Nordström, Jakob
    LTU.
    A systematic evaluation of devices for measuring abrasive wear of mill liners2009Inngår i: 22nd International Congress on Condition Monitoring and Diagnostic Engineering Management: COMADEM 2009 ; June 9 - 11, 2009, San Sebastian, Spain, Miramar Palace / [ed] Aitor Arnaiz, Eibar: Fundaci n Tekniker , 2009, s. 419-427Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Inspection of the liner wear in the mill of an ore dressing plant is one of the critical parameters in the context of mill downtime and production performance. The total downtime cost during measurement can be reduced by a significant fraction by using appropriate measurement devices. Due to the different quality dimensions of a measuring device, e.g. the cost, accuracy, reliability and accessibility, it is necessary to select an appropriate device based on the specific needs of the industry. Customer satisfaction is perhaps the most important performance measure for the service quality of the device, and therefore this paper provides an approach to define the customer satisfaction with reference to the mentioned quality dimensions. The main aim of this paper is to determine a unified measure or quality index for the service quality of the measurement device across all the dimensions. Each quality index will then correspond to the total predicted usability of the particular measurement method based on the industry needs. Furthermore, this study also discusses the advantages and disadvantages of existing measurement methods and proposes an indirect measurement method to reduce the downtime during inspection.

  • 14.
    Dandotiya, Rajiv
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Wijaya, Andi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Evaluation of abrasive wear measurement devices of mill liners2011Inngår i: International Journal of COMADEM, ISSN 1363-7681, Vol. 14, nr 2, s. 3-17Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Measurement of the liner wear in the mill of an ore dressing plant is one of the critical parameters in the context of mill downtime and production performance. The total downtime cost during measurement can be reduced by a significant fraction by using appropriate measurement devices. Due to the different quality attributes of a measuring device, e.g. the cost, accuracy, reliability and accessibility, it is necessary to select an appropriate device based on the specific needs of the industry. The main aim of this study is to determine a unified measure or quality index for the service quality of the measurement device across selected attributes. Each quality index will then correspond to the total predicted usability of the particular measurement method based on the industry needs. Furthermore, this study includes test of selected measurement methods and discusses the advantages and disadvantages for the same. It also proposes a new concept of an indirect measurement method to reduce the downtime during inspection.

  • 15. Eriksson, Erland
    et al.
    Nygård, Sven
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Lundberg, Jan
    Electrical resistivity and conductivity of greases: an initial study2002Inngår i: Lubrication Science, ISSN 0954-0075, E-ISSN 1557-6833, Vol. 15, nr 1, s. 33-50Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Investigations of railway wagons fitted with rolling-element bearings have shown damage to the bearings from the passage of electric current. This also occurs in railway wagons without an electric energy consumption of their own, because of residual currents from electric locomotives. This phenomenon gives rise to technical, financial, and even safety problems. This paper reviews research in the field of rolling-element bearings exposed to electric currents. The paper also reports on an ongoing study undertaken to understand the mechanism of current flow and the role of lubricants in the associated damage, and to identify the possibilities of minimising bearing damage. The obvious solution to this problem is to use optimised greases, i.e., with high electrical conductivity and good lubricating ability. In the preliminary work reported here a number of greases for railway use were tested to determine their electrical conductivity in static and dynamic situations. These tests were performed using specially designed apparatus, and significant initial information about the electrical properties of greases has been obtained in this research, for example, that there is a correlation between the electrical conductance under static and dynamic conditions. All the greases tested showed comparatively high resistivity values, which could be one explanation for the bearing damage observed.

  • 16. Eriksson, Erland
    et al.
    Nygård, Sven
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Lundberg, Jan
    Electrical resistivity and conductivity of greases: an initial study2000Inngår i: 9th Nordic Symposium on Tribology: NORDTRIB 2000 : Porvoo, Finland, 11-14 June 2000 / [ed] Peter Andersson; Helena Ronkainen; Kenneth Holmberg, Espoo: Technical Research Centre of Finland (VTT) , 2000, s. 671-683Konferansepaper (Fagfellevurdert)
  • 17.
    Haarakoski, Milla
    et al.
    University of Lapland, Rovaniemi.
    Johansson, Maria
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Innovation och Design.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    A guide to methods for small and medium sized enterprises (SMEs) designing for new markets, based on cultural research experiences2006Inngår i: Wonderground: Design Research Society International Conference 2006, Proceeding book / [ed] Ken Friedman; Terence Love; Eduardo Côrte-Real; Chris Rust, Lisbon: CEIADE – Centro Editorial do IADE , 2006Konferansepaper (Fagfellevurdert)
  • 18.
    Hamodi, Hussan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Ahmadzadeh, Farzaneh
    Division of Product Realization, Mälardalen University, Eskilstuna.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Ghodrati, Behzad
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Economic lifetime prediction of a mining drilling machine using an artificial neural network2014Inngår i: International Journal of Mining, Reclamation and Environment, ISSN 1748-0930, E-ISSN 1748-0949, Vol. 28, nr 5, s. 311-322Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This study develops models for predicting the economic lifetime of drilling machines used in mining. It uses three cases, each represented by a MATLAB code, to develop an optimisation model. The resulting ORT is fed as input to an artificial neural network (ANN) and the results translated into a relatively simple equation. The study finds that increasing the purchase price and decreasing the operating and maintenance costs will increase a machine's ORT linearly. Decreased maintenance cost has the largest impact on ORT, followed by increased purchase price and decreased operating cost. The ANN method gives a series of basic weight and response functions which can be made available to any engineer without the use of complicated software. It also helps decision-makers determine the best time economically to replace an old machine with a new one; thus, it can be extended to more general applications in the mining industry

  • 19.
    Hamodi, Hussan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Hoseinie, Hadi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Monte Carlo Reliability Simulation of Underground Drilling Rigs2015Konferansepaper (Fagfellevurdert)
  • 20.
    Hamodi, Hussan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Hoseinie, Hadi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Monte Carlo Reliability Simulation of Underground Mining Drilling Rig2016Inngår i: Current Trends in Reliability, Availability, Maintainability and Safety: An Industry Perspective / [ed] Uday Kumar; Alireza Ahmadi; Ajit Kumar Verma; Prabhakar Varde, Encyclopedia of Global Archaeology/Springer Verlag, 2016, s. 633-643Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Drilling rigs are widely used in mine development or construction and tunnel engineering projects. The rig consists of 12 subsystems in a series configuration and can be driven by diesel or electrical engines. This paper uses the Kamat-Riley (K-R) event-based Monte Carlo simulation method to perform reliability analysis of an underground mine drilling rig. For data analysis and to increase statistical accuracy, the paper discusses three case studies in an underground mine in Sweden. Researchers built a process to programme the simulation process and used MATLABTM software to run simulations. The results showed the simulation approach is applicable to the reliability analysis of this rig. Moreover, the reliability of all rigs reaches almost zero value after 50 h of operation. Finally, the differences between the reliability of the studied fleet of drilling rigs are a maximum 10 %. Therefore, all maintenance or spare part planning issues can be managed in a similar way

  • 21.
    Hamodi, Hussan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Replacement team of mining drilling rigs2014Inngår i: Proceedings of Maintenance Performance Measurement and Management: th - 5th September 2014 Coimbra, Portugal : (MPMM 2014), 2014Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents a practical model to calculate the optimal replacement time (ORT) of drilling rigs used in underground mining. As a case study, cost data for drilling rig were collected over four years from a Swedish mine. The cost data include acquisition, operating, maintenance and downtime costs when using a redundant rig. A discount rate is used to determine the value of these costs over time. The study develops an optimisation model to identify the ORT of a mining drilling rig which represents a key performance indicator. It uses an artificial neural network (ANN) technique to identify the effect of the various cost factors on the ORT. The absolute ORT in the case study is 87 months, and there is an optimal replacement range within which the company can replace the rig. The results also show that the redundant rig cost has the largest impact on the ORT followed by acquisition, maintenance and operating costs. Regression analysis shows a linear relationship between the cost factors and the ORT of the drilling rig.

  • 22.
    Hamodi, Hussan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Al-Gburi, Majid
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Ahmadi, Alireza
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Ghodrati, Behzad
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Model for economic replacement time of mining production rigs including redundant rig costs2015Inngår i: Journal of Quality in Maintenance Engineering, ISSN 1355-2511, E-ISSN 1758-7832, Vol. 21, nr 2, s. 207-226Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose - This paper presents a practical model to determine the economic replacement time (ERT) of production machines. The objective is to minimise the total cost of capital equipment, where total cost includes acquisition, operating, maintenance costs and costs related to the machine’s downtime. The costs related to the machine’s downtime are represented by the costs of using a redundant machine. Design/methodology/approach - Four years of cost data are collected. Data is analysed, practical optimisation model is developed and regression analysis is done to estimate the drilling rigs ERT. The artificial neural network (ANN) technique is used to identify the effect of factors influencing the ERT of the drilling rigs.Findings - The results show that the redundant rig cost has the largest impact on ERT, followed by acquisition, maintenance and operating costs. The study also finds that increasing redundant costs per hour have a negative effect on ERT, while decreases in other costs have a positive effect. Regression analysis shows a linear relationship between the cost factors and ERT. Practical implications - The proposed approach can be used by the decision maker in determining the economic replacement time of production machines which used in mining industry.Originality/value - The research proposed in this paper provides and develops an optimisation model for economic replacement time of mining machines. This research also identifies and explains the factors that have the largest impact on the production machine’s ERT. This model for estimating the ERT has never been studied on mining drilling rigs.Keywords Decision support model, Life cycle cost, Optimisation, Replacement timePaper type Research paper

  • 23.
    Hamodi, Hussan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Jonsson, Adam
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Matematiska vetenskaper.
    Economic lifetime of a drilling machine: a case study on mining industry2013Inngår i: MPMM 2013 (Maintenance Performance Measurement and Management) / [ed] sari Monto; Miia Pirttilä; Timo Kärri, Lappeenranta, Finland: MPMM 2013 , 2013, s. 138-147Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Underground mines use many different types of machinery during the drift mining processesof drilling, charging, blasting, loading, scaling and bolting. Drilling machines play a criticalrole in the mineral extraction process and thus are important economically. However, as themachines age, their efficiency and effectiveness decrease, negatively affecting productivityand profitability and increasing total cost. Hence, the economic replacement lifetime of themachine is a key performance indicator. This paper introduces an optimisation model thatgives the optimal lifetime for a drilling machine. A case study has been done at anunderground Swedish mine to identify the economic replacement time of a drilling machine.It considers the purchase price, maintenance and operation costs, and the machine’s secondhandvalue. Findings show that the economic replacement lifetime of a drilling machine inthis mine is 96 months. The proposed model can be used for other underground miningmachines.

  • 24.
    Hamodi, Hussan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Jonsson, Adam
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Matematiska vetenskaper.
    Economic lifetime of a drilling machine: a case study on mining industry2015Inngår i: International Journal of Strategic Engineering Asset Management (IJSEAM), ISSN 1759-9733, E-ISSN 1759-9741, Vol. 2, nr 2, s. 177-189Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Underground mines use many different types of machinery duringthe drift mining processes of drilling, charging, blasting, loading, scaling andbolting. Drilling machines play a critical role in the mineral extraction processand thus are important economically. However, as the machines age, theirefficiency and effectiveness decrease, negatively affecting productivity andprofitability and increasing total cost. Hence, the economic replacementlifetime of the machine is a key performance indicator. This paper introducesan optimisation model that gives the optimal lifetime for a drilling machine. Acase study has been done at an underground Swedish mine to identify theeconomic replacement time of a drilling machine. It considers the purchaseprice, maintenance and operation costs, and the machine’s second-hand value.Findings show that the economic replacement lifetime of a drilling machine inthis mine is 96 months. The proposed model can be used for other undergroundmining machines.

  • 25.
    Hamodi, Hussan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Jonsson, Adam
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Matematiska vetenskaper.
    Ahmadi, Alireza
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Case Study: Model for economic lifetime of drilling machines in the Swedish mining industry2015Inngår i: The Engineering Economist, ISSN 0013-791X, E-ISSN 1547-2701, Vol. 60, nr 2, s. 138-154Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The purpose of this paper is to develop a practical economic replacement decision model to identify the economic lifetime of a mining drilling machine. A data driven optimisation model was developed for operating and maintenance costs, purchase price and machine resale value. Equivalent present value of these costs by using discount rate was considered. The proposed model shows that the absolute optimal replacement time (ORT) of a drilling machine used in one underground mine in Sweden is 115 months. Sensitivity and regression analysis show that the maintenance cost has the largest impact on the ORT of this machine. The proposed decision making model is applicable and useful and can be implemented within the mining industry.

  • 26.
    Hamodi, Hussan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Wijaya, Andi
    Ghodrati, Behzad
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Downtime analysis of drilling machines and suggestions for improvements2014Inngår i: Journal of Quality in Maintenance Engineering, ISSN 1355-2511, E-ISSN 1758-7832, Vol. 20, nr 4, s. 306-332Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose– The purpose of this paper is to analyse and compare the downtime of four drilling machines used in two underground mines in Sweden. The downtime of these machines was compared to show what problems affect downtime and which strategies should be applied to reduce it.Design/methodology/approach– The study collects failure data from a two-year period for four drilling machines and performs reliability analysis. It also performs downtime analysis utilising a log-log diagram with a confidence interval.Findings– There are notable differences in the downtime of most of the studied components for all machines. The hoses and feeder have relatively high downtime. Depending on their downtime, the significant components can be ranked in three groups. The downtime of the studied components is due to reliability problems. The study suggests the need to improve the reliability of critical components to reduce the downtime of drilling machines.Originality/value– The method of analysing the downtime, identifying dominant factors and the interval estimation for the downtime, has never been studied on drilling machines. The research proposed in this paper provides a general method to link downtime analysis with potential component improvement. To increase the statistical accuracy; four case studies was performed in two different mines with completely different working environment and ore properties. Using the above method showed which components need to be improved and suggestions for improvement was proposed and will be implemented accordingly.

  • 27.
    Holgerson, Mikael
    et al.
    Luleå tekniska universitet.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Engagement behaviour of a paper-based wet clutch: Part 1: Influence of drive torque1999Inngår i: Proceedings of the Institution of mechanical engineers. Part D, journal of automobile engineering, ISSN 0954-4070, E-ISSN 2041-2991, Vol. 213, nr 4, s. 341-348Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Owing to increasing demands when designing wet clutches for automatic transmissions, more knowledge about their behaviour is needed. In cars with power shifting automatic transmissions, an engine torque is continuously transmitted through the gear box. Most experimental and theoretical work concerning investigations of wet clutches today uses the inertia type of test apparatus, e.g. the SAE test machine 2. However, this type of test machine has no possibility of investigating the influence of a drive torque from the power supply. In order to investigate the influence of drive torque on wet clutch engagements, a new type of apparatus was built, which can operate with different combinations of inertia and drive torque. This apparatus can perform engagements more similar to those in automatic transmissions. The aim of this paper was to compare experimental outputs obtained using these principles of testing, concerning the influence of drive torque. It was found that the friction characteristics of wet clutches are independent of how the input energy is produced. This means that friction can be investigated with both principles. It was also found that an apparatus using only inertia gives shorter engagement times and higher temperatures than an apparatus including a drive torque at the same level of input energy. This can be explained by different power characteristics. Therefore, when investigating temperatures of wet clutch engagements, one must be careful when translating the results into reality.

  • 28.
    Holgerson, Mikael
    et al.
    Luleå tekniska universitet.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Engagement behaviour of a paper-based wet clutch: Part 2: Influence of temperature1999Inngår i: Proceedings of the Institution of mechanical engineers. Part D, journal of automobile engineering, ISSN 0954-4070, E-ISSN 2041-2991, Vol. 213, nr 5, s. 449-455Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    To increase comfort, performance and fuel economy, a more careful optimization of automatic transmissions is needed. Of special interest is how the temperature influences the engagement characteristics. In order to increase the level of knowledge in this area, a wet clutch test rig including a drive torque and inertia was used. The temperature and the developed energy were varied in order to investigate their influence on the characteristics of an engagement. As a consequence the influence of instant temperature, maximum temperature and instant normal force was also studied. Some of the most important conclusions of the investigation are that both the dynamic and static friction coefficients slightly decrease and the engagement time increases with increasing temperature. It was also found that the static and dynamic friction coefficients are not influenced by energy if the instant temperature is the same. An important parameter that describes the risk of stick-slip is the quotient between the static and dynamic friction. It was found that this quotient decreases with increasing temperature, and thus the risk of stick-slip is also supposed to decrease.

  • 29.
    Håkansson, Anders
    et al.
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Innovation och Design.
    Lundberg, Jan
    A Systematic Evaluation of RT Methods for SME:s2004Inngår i: Time-compression technologies, Europe : the magazine for fast and efficient design engineering teams, ISSN 1467-1360, Vol. 12, nr 4, s. 20-27Artikkel i tidsskrift (Fagfellevurdert)
  • 30.
    Håkansson, Anders
    et al.
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Innovation och Design.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Use of external facilitator to choose optimal Rapid Tooling method: A case study2013Inngår i: High Value Manufacturing: Advanced research in virtual and rapid prototyping, Leiden: CRC Press, Taylor & Francis Group , 2013, s. 379-384Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Purpose - The purpose of this study is to investigate whether the use of an external expert, called facilitator in this study, can assist a company with little previous knowledge within the field of Rapid Prototyping, called RP in this study, first to determine if they would benefit from RP and if so, find which components that are suitable for RP, and second to find the optimum RP method and RP service bureau. Design/methodology/approach - The study was made as action research, where the researcher actively participated in the project acting as the facilitator. The company involved had a clear ambition to make their prototyping more effective and wanted to know if RP could be useful in this ambition. Findings - The results show that the facilitator's assistance was useful to the company. Within two weeks, a component was selected, a suitable RP method was found and a RP service bureau was contacted. Without this extra expertise, the company could have difficulties identifying the internal needs, the demands to put to the RP method and to choose suitable method and contractor. By acting in the company's interest, the facilitator ensures an objective selection of RP method and that it is optimized for the current situation. Originality/value - This study is not on finding a new method for selecting the best RP method. The main objective for this study is to find a way to make these selection methods, and also the RP technology, available to companies new to the technology while the company's interest is kept in focus.

  • 31.
    Höglund, Erik
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Influence of limiting shear stress of oils on failure of a lubricating oil film1992Inngår i: Vol. 11, nr 2-4Artikkel i tidsskrift (Fagfellevurdert)
  • 32.
    Jönsson, Jens
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Arasteh Khouy, Iman
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Rantatalo, Matti
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Nissen, Arne
    Trafikverket.
    Measurement of vertical geometry variations in railway turnouts exposed to different operating conditions2016Inngår i: Proceedings of the Institution of mechanical engineers. Part F, journal of rail and rapid transit, ISSN 0954-4097, E-ISSN 2041-3017, Vol. 230, nr 2, s. 486-501Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Turnouts are critical units in a railway system; they perform the switching procedure that allows trains to change between routes. Monitoring the track geometry of a turnout is necessary for maintenance planning and design optimisation. Monitoring is usually done by track recording cars, however, to isolate the ageing and dynamic behaviour of the track it is also necessary to study the unstressed track geometry of the turnouts. Such measurements can be used to develop degradation models to optimise maintenance and design, thereby increasing availability and reducing life cycle cost. This paper introduces a new method to measure the vertical position of the track geometry over time during non-operational conditions (unstressed) to show track degradation. The new method includes a smart system that uses relative measurement reference points to create a better accuracy and lower costs compared with fixed reference points. It evaluates various types of measurement equipment and uses levelling equipment to measure the unstressed vertical geometry of 13 turnouts located on Swedish railway lines, with three follow-up measurements over a year and a half. The turnouts were categorised into four groups: based on their accumulated capacity in million gross tonnes (MGT) and whether they were on a straight or curved main track. Surprisingly, the first three measurements showed the geometry of turnouts on the straight main track to have a vertical elevation tendency towards the mid-section, whereas the turnouts on the curved main track had a general vertical downwards bend tendency towards the mid-section. The results also showed that a higher capacity in MGT has a greater influence on track geometry changes over time.

  • 33.
    Kassfeldt, Elisabet
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lubricant capability in squeeze-sliding motion1993Inngår i: Thin films in tribology: proceedings of the 19. Leeds-Lyon Symposium on Tribology, held at the Institute of Tribology, University of Leeds, U.K., 8. - 11. September 1992 / [ed] Duncan Dowson, Amsterdam: Elsevier, 1993, s. 255-261Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Nine different types of commercial lubricants have been tested in an apparatus which can produce squeeze and sliding motion simultaneously. It is found that lubricants with the same viscosity show big differences in lubricant capability in terms of wear and oil film collapse, and that these differences are due to the additives

  • 34.
    Khan, Saad Ahmed
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Stenström, Christer
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Carry distance of top-of-rail friction modifiers2018Inngår i: Proceedings of the Institution of mechanical engineers. Part F, journal of rail and rapid transit, ISSN 0954-4097, E-ISSN 2041-3017, Vol. 232, nr 10, s. 2418-2430Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Rail issues such as corrugation, rolling contact fatigue, noise and wear have been increasing with the increase in railway traffic. The application of top-of-rail friction modifiers (TOR-FMs) is claimed by their manufacturers in the railway industry to be a well-established technique for resolving the above-mentioned issues. There are various methods for applying friction modifiers at the wheel–rail interface, among which stationary wayside systems are recommended by TOR-FM manufacturers when a distance of a few kilometres is to be covered. TOR-FM manufacturers also claim that by using wayside equipment, the TOR-FM can be spread over a minimum distance of 3 km, over which it maintains a coefficient of friction of µ = 0.35 ± 0.05. To determine the carry distance of TOR-FMs, some researchers use tribometers to measure the coefficients of friction. However, moisture and deposits from the environment and trains can alter the top-of-rail friction and give a misleading indication of the presence of a friction modifier. Therefore, the coefficient of friction itself is not a clear indicator of the presence of TOR-FMs. In the present study, cotton swabs dipped in a mixture of alcohol and ester were used to collect surface deposits (a third body) from both the wheel and rail at various distances from the point of application. Subsequently, the third body collected on the cotton swab was analysed using an energy dispersive X-ray analysis. The results have shown that the maximum carry distance of TOR-FMs on the top of the rail is limited to 70 m when using a TOR-FM from one manufacturer and to 450 m when using a TOR-FM from another manufacturer. The carry distance on the contact band of the wheel is limited to 100 m and 340 m. The friction modifier on the edges of the contact band was detected over a distance of up to 3 km; however, this will not minimise the damage or friction at the wheel–rail interface.

  • 35.
    Khan, Saad Ahmed
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Persson, Ingemar
    AB DEsolver, Östersund, Sweden.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Stenström, Christer
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Prediction of the effects of friction control on top-of-rail cracks2018Inngår i: Proceedings of the Institution of mechanical engineers. Part F, journal of rail and rapid transit, ISSN 0954-4097, E-ISSN 2041-3017, Vol. 232, nr 2, s. 484-494Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Rolling contact fatigue is a major problem connected with railway tracks, especially in curves, since it leads to highermaintenance costs. By optimising the top-of-rail friction, the wear and cracks on the top of the rail can eventually bereduced without causing very long braking distances. There are several research articles available on crack prediction,but most of the research is focused either on rail without a friction modifier or on wheels with and without frictioncontrol. In the present study, in order to predict the formation of surface-initiated rolling contact fatigue, a range offriction coefficients with different Kalker’s reduction factors has been assumed. Kalker’s reduction factor takes care ofthe basic tendency of creepage as a function of the traction forces at lower creepage. The assumed range covers possiblefriction values from those for non-lubricated rail to those for rail with a minimum measured friction control on the top ofthe rail using a friction modifier. A fatigue index model based on the shakedown theory was used to predict thegeneration of surface-initiated rolling contact fatigue. Simulations were performed using multi-body simulation, forwhich inputs were taken from the Iron Ore line in the north of Sweden. The effect of friction control was studiedfor different curve radii, ranging from 200 m to 3000 m, and for different axle loads from 30 to 40 tonnes at a constanttrain speed of 60 km/h. One example of a result is that a maximum friction coefficient (m) of 0.2 with a Kalker’s reductionfactor of 15% is needed in the case of trains with a heavy axle load to avoid crack formation.

  • 36.
    Khan, Saad Ahmed
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Persson, Ingemar
    AB DEsolver, Östersund.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Stenström, Christer
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Prediction of top-of-rail friction control effects on rail RCF suppressed by wear2017Inngår i: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 380-381, s. 106-114Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Rolling contact fatigue (RCF) and wear, two major deterioration processes, limit the lifetime of rails. These deterioration processes are even more severe on the curves of tracks used by heavy haul trains. Because wear is a material removing process, it can suppress the formation of RCF (also known as surface initiated cracks). In railways, cracks have a higher risk of instigating a catastrophic failure than wear; hence, it is comparatively better to have wear than to have cracks. By controlling the top-of-rail friction, both of these deteriorating processes can be reduced to enhance the lifetime of rails. In order to achieve these possible advantages, the infrastructure manager of the Swedish railway is planning to implement a top-of-rail friction control technology on the iron ore line in northern Sweden wherein RCF is a major problem on the curves. The present study uses a damage index model in a multi-body simulation software and predicts the probability of RCF formation with suppressing effect of wear for different friction control values. The effect of friction control is simulated on curve radii ranging from 200 to 3,000 m and axle loads ranging from 30 to 40 t at a constant train speed of 60 km/h. Findings show that on a very sharp circular curve, radius < 300 m, RCF can be eliminated without friction control due to the high wear rate. On moderate curves, 300 < radius < 1,000 m, a friction coefficient (µ) of, at most, 0.3 with a Kalker's coefficient of, at most, 30% is required to avoid RCF

  • 37. Kumar, Rupesh
    et al.
    Chaikumarn, Montakarn
    Lundberg, Jan
    Participatory ergonomics and an evaluation of a low-cost improvement effect on cleaners' working posture2005Inngår i: International Journal of Occupational Safety and Ergonomics, ISSN 1080-3548, E-ISSN 2376-9130, Vol. 11, nr 2, s. 203-210Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Cleaning is a highly physically demanding job with a high frequency of awkward postures and working environments as contributing risk factors. Participatory ergonomics is a method in which end-users take an active role in identifying risk factors and solutions. The aim of this study was to apply the participatory ergonomics method to identify cleaning problems and to evaluate the effect of a low-cost improvement on cleaners' working postures in an office environment. The results show that the cleaning problem was identified, and the low-cost ergonomics solution suggested by the cleaners was implemented. Thus an improved working environment reduced the number of awkward cleaning postures and the Ovako Working Posture Analysis System (OWAS) action category for floor mopping decreased. It can be concluded that working in an improved environment can lead to better working postures which, in turn, leads to the cleaners' better health and better cleaning results.

  • 38.
    Lanke, Amol
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Ghodrati, Behzad
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Production improvement techniques in process industries for adoption in mining: A comparative study2016Inngår i: International Journal of Productivity and Quality Management, ISSN 1746-6474, E-ISSN 1746-6482, Vol. 19, nr 3, s. 366-386Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    High profitability and customer satisfaction are of supreme importance for any business. To achieve both objectives, an organisation must design a structured approach. To achieve profitability, organisations look to principles of lean manufacturing and techniques such as EFQM, business excellence. This paper reviews such methodologies across different industries, comparing techniques and elements. Its objective is to determine which methodologies are most applicable to the Swedish mining industry and propose a method to achieve lean mining. To this end, the paper looks at the methodologies of a food manufacturing industry, an automobile component manufacturing company, the manufacturing and service sector, and the oil and gas industry. It finds that the method used in the oil and gas industry is more relevant to mining, even though it has some flaws. Further research is needed to adapt this method to the mining industry.

  • 39.
    Larsson, Roland
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Lundberg, Jan
    Observations in transiently loaded EHL contacts under pure sliding conditions1998Inngår i: Tribology Transactions, ISSN 1040-2004, E-ISSN 1547-397X, Vol. 41, nr 4, s. 489-496Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An elastohydrodynamically lubricated contact is experimentally investigated during loading and pure sliding motion. This is a combination of motions where lubricant film failures sometimes occur. The experimental setup consists of a 70-mm diam. ball segment mounted on a pendulum. The ball segment can be rotated while it impacts a lubricated glass disc. The deformation of the surfaces in the contact region is studied by means of optical interferometry and high-speed video recording equipment. Two poly-α-olefin-type lubricants with viscosities of 94 and 2600 mm2/s are used in the experiments. The squeeze velocity, i.e., the normal approach velocity, is approximately 0.06 m/s, giving an impact time of about 20 ms. The sliding velocity is varied from 0 to 34 m/s. Some of the observed phenomena are that lubricant film breakdown occurs at high sliding velocities while full film is maintained at no or low sliding velocity and that the traditional horseshoe-shaped fringes are found even for this load situation. At very high sliding velocities, the interferograms are distorted from their normal circular shape to a pear-like shape. (

  • 40.
    Larsson, Roland
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Simplified solution to the combined squeeze-sliding lubrication problem1994Inngår i: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 173, nr 1-2, s. 85-94Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The unfavourable elastohydrodynamic lubrication situation in combined squeeze and sliding motion has been analysed both theoretically and experimentally. In experiments a rotating roller impacted and rebounded on a lubricated surface. It was found that oil film breakdown always occurs at the end of the impact time, when the contact force is low. It has also been found that there exists an upper limit for the sliding velocity. Below this limiting velocity no oil film breakdown occurs. This paper is an initial attempt to explain theoretically why oil film breakdown takes place towards the end of the impact, and why an increasing sliding velocity reduces the capability of the oil film to separate the lubricated surfaces. If the oil film's elastic and damping behaviour are taken into consideration it can be shown that a considerable phase shift between maximum contact force and oil film breakdown will arise. It has been found that the squeeze action dominates the pressure formation in the contact and thus the hydrodynamic effect of sliding motion is moderate. Furthermore, several effects, such as non-Newtonian behaviour, surface roughness, temperature rise, starvation and deformations, which are not included in the theoretical model, may decrease the oil film thickness if the sliding velocity increases

  • 41.
    Larsson, Roland
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Lundberg, Jan
    Study of lubricated impact using optical interferometry1994Inngår i: Frontiers in tribology: proceedings of the 4th International Tribology Conference - AUSTRIB '94, Perth, Western Australia, 5 - 8 Decemnber 1994 / [ed] G.W. Stachowiak, Perth, 1994Konferansepaper (Fagfellevurdert)
  • 42.
    Larsson, Roland
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Lundberg, Jan
    Study of lubricated impact using optical interferometry1995Inngår i: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 190, nr 2, s. 184-189Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An experimental study of lubricated impacts between a steel ball and a flat glass surface has been performed. The experimental set-up consists of a Ø70 mm ball mounted on a pendulum which impacts onto a lubricated glass disc. The contact region is studied by means of optical interferometry using a monochromatic light source, a microscope and a high-speed video recording equipment. The lubricants are of PAO type and the viscosity ranges from 27 to 2600 mm2 s-1 at the test temperature. The impact velocity is varied between 0.08 and 0.29 m s-1. A dimple occurs at the centre of the contact where the lubricant is trapped. The influence of viscosity and impact velocity on the dimple's depth and diameter is studied.

  • 43.
    Lemma, Yonas
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Asplund, Matthias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Rantatalo, Matti
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Top-of-Rail Friction Measurements of the Swedish Iron Ore Line2014Inngår i: Proceedings of the 3rd international workshop and congress on eMaintenance: June 17-18 Luleå, Sweden : eMaintenance, Trends in technologies & methodologies, challenges, possibilites and applications / [ed] Uday Kumar; Ramin Karim; Aditya Parida; Philip Tretten, Luleå: Luleå tekniska universitet, 2014, s. 3-7Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Friction management in the railway industry is a well-establishedtechnology with the aim of optimizing the friction between wheeland rail. Determining the friction coefficient (Q) at the wheel-railinterface is therefore important especially for heavy haul lineswith higher axel loads. This paper presents an initial study of thetop-of-rail friction condition of a 30 ton axel load, Iron Ore line inthe northern part of Sweden. The friction coefficient between therail and a metal wheel of a portable Tribometer was measured atdifferent geographical locations and during differentenvironmental conditions. The effects of precipitation are studiedand compared with the effects of top of rail friction modifiers. Themeasurements of not lubricated line sections showed valuesaround Q 0.6 compared to Q 0.3 for areas with e.g. top-of- raillubrication. During snowy conditions a decrease in friction couldalso be detected.

  • 44.
    Lindgren, Victoria
    et al.
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Innovation och Design.
    Gärling, Anita
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Arbetsvetenskap.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Designing driver environments for the elderly driver2006Konferansepaper (Annet vitenskapelig)
  • 45.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    A new test apparatus for estimation of friction in grease-lubricated rolling element bearings in cold conditions1997Inngår i: Proceedings of the fifth International Symposium on Cold Region Development, Anchorage, Alaska, USA, May 4-10, 1997, International Association of Cold Regions Development Studies , 1997, s. 625-628Konferansepaper (Fagfellevurdert)
  • 46.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Apparatus for squeeze/sliding lubrication studies1990Inngår i: Nordtrib'90: proceedings of the 4th Nordic Symposium on Tribology, Lubrication, Friction and Wear; 10th - 13th June 1990, Hirtshals, Denmark / [ed] Jørgen Jakobsen; Mads Klarskov; Michael Eis, Lyngby: NORDTRIB , 1990Konferansepaper (Fagfellevurdert)
  • 47.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Emulsioners viskositet vid plan poiseuille strömning1984Rapport (Annet vitenskapelig)
  • 48.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Emulsioners viskositet vid poiseuille strömning1984Inngår i: Tribologia : Finnish Journal of Tribology, ISSN 0780-2285, Vol. 3, nr 4, s. 43-68Artikkel i tidsskrift (Fagfellevurdert)
  • 49. Lundberg, Jan
    Grease-lubrication of roller bearings in railway waggons. Part 1: Field tests and systematic evaluation to determine the optimal greases2000Inngår i: Industrial Lubrication and Tribology, ISSN 0036-8792, E-ISSN 1758-5775, Vol. 52, nr 1, s. 36-43Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Describes a comprehensive field test to determine the best grease for spherical roller bearings in railway waggon wheels and increase the knowledge of grease lubrication. Nine different fully-formulated commercial greases were examined in the wheel bearings of five ore waggons, used for transporting ore commercially by railroad from the Kiruna Mine in northern Sweden to Narvik in northern Norway for shipping to foreign markets. After the end of the test period, the wear and electrical damage, as well as the rust on the bearings, were also studied. In order to find out the optimum grease for this application, draws up a specification of requirements and uses a systematic approach to development of an evaluation method that could be applied to greases in actual service.

  • 50.
    Lundberg, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Increased production systems effectiveness through condition monitoring and prognostics2010Inngår i: Bergforsk 2010: mineral supply - a grand challenge and opportunity / [ed] Göran Bäckblom, 2010, s. 21-23Konferansepaper (Annet vitenskapelig)
123 1 - 50 of 106
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