Change search
Link to record
Permanent link

Direct link
Publications (10 of 99) Show all publications
Moosazadeh, S., Hoseinie, S. H. & Ghodrati, B. (2023). Effects of mixed-ground condition on tool life and cutterhead maintenance of tunnel boring machines. International Journal of Systems Assurance Engineering and Management, 14(6), 2586-2594
Open this publication in new window or tab >>Effects of mixed-ground condition on tool life and cutterhead maintenance of tunnel boring machines
2023 (English)In: International Journal of Systems Assurance Engineering and Management, ISSN 0975-6809, E-ISSN 0976-4348, Vol. 14, no 6, p. 2586-2594Article in journal (Refereed) Published
Place, publisher, year, edition, pages
Springer Nature, 2023
National Category
Other Civil Engineering Geotechnical Engineering
Research subject
Operation and Maintenance Engineering
Identifiers
urn:nbn:se:ltu:diva-101796 (URN)10.1007/s13198-023-02121-w (DOI)2-s2.0-85171273792 (Scopus ID)
Note

Validerad;2023;Nivå 2;2023-12-06 (hanlid)

Available from: 2023-10-27 Created: 2023-10-27 Last updated: 2023-12-06Bibliographically approved
Rahimdel, M. J. & Ghodrati, B. (2023). Reliability analysis of the compressed air supplying system in underground mines. Scientific Reports, 13, Article ID 6836.
Open this publication in new window or tab >>Reliability analysis of the compressed air supplying system in underground mines
2023 (English)In: Scientific Reports, E-ISSN 2045-2322, Vol. 13, article id 6836Article in journal (Refereed) Published
Abstract [en]

Despite the high cost and low efficiency, compressed air is mostly used in underground mining for ore extraction, hoisting, and mineral processing operations. Failures of compressed air systems not only threaten the health and safety of workers but also contribute to inefficient control of airflow and stopped all equipment that operates by compressed air. In such uncertain conditions, mine managers are faced with the big challenge to supply enough compressed air, and therefore, the reliability evaluation of these systems is essential. This paper aims to analyze the reliability of the compressed air system using the Markov modeling approach as a case study, Qaleh-Zari Copper Mine, Iran. To achieve this, the state space diagram was constructed considering all relevant states for all compressors in the main compressor house of the mine. The failure and repair rate of all main and reserve compressors were calculated for all possible transitions between states to obtain the probability of being of the system in each of the states. Moreover, the probability of failure at any time period was considered to study the reliability behavior. The results of this study show that there is 31.5% probability that the compressed air supplying system is in operating condition with two main and one standby compressors. The system probability that two main compressors are remain in the operation without failure for one months is 92.32%. Furthermore, the lifetime of the system is estimated 33 months when at least one main compressor is active.

Place, publisher, year, edition, pages
Springer Nature, 2023
National Category
Other Civil Engineering
Research subject
Operation and Maintenance Engineering
Identifiers
urn:nbn:se:ltu:diva-97072 (URN)10.1038/s41598-023-33736-5 (DOI)37100840 (PubMedID)2-s2.0-85153913163 (Scopus ID)
Note

Validerad;2023;Nivå 2;2023-05-10 (hanlid)

Available from: 2023-05-10 Created: 2023-05-10 Last updated: 2023-05-10Bibliographically approved
Allahkarami, Z., Sayadi, A. R. & Ghodrati, B. (2022). Mixed-effects model for reliability assessment of dump trucks in heterogeneous operating environment: A case study. Quality and Reliability Engineering International, 38(5), 2881-2898
Open this publication in new window or tab >>Mixed-effects model for reliability assessment of dump trucks in heterogeneous operating environment: A case study
2022 (English)In: Quality and Reliability Engineering International, ISSN 0748-8017, E-ISSN 1099-1638, Vol. 38, no 5, p. 2881-2898Article in journal (Refereed) Published
Abstract [en]

Reliability of mining equipment is influenced by different operational and environmental risk factors. However, in practice, including all relevant factors in reliability analysis is not possible. Ignoring the risk factors leads to unobserved heterogeneity and biased estimation of reliability characteristics. This research proposes a semi-parametric mixed-effects model to assess the simultaneous effects of observed and unobserved risk factors on reliability. Furthermore, the model can be used for investigating inter-cluster dependency and variability. To illustrate the model, a comprehensive case study is presented using data from three mines in Iran. The results show that the model can address the effect of unobserved risk factors. Moreover, it is found that the hazard of dump trucks is significantly associated with operator skill, season and the elevation difference between dumping and loading points.

Place, publisher, year, edition, pages
John Wiley & Sons, 2022
Keywords
frailty, heterogeneity, maintenance, mining, mixed-effects model, reliability, unobserved risk factor
National Category
Other Civil Engineering
Research subject
Operation and Maintenance
Identifiers
urn:nbn:se:ltu:diva-89538 (URN)10.1002/qre.3079 (DOI)000750203900001 ()2-s2.0-85124145005 (Scopus ID)
Note

Validerad;2022;Nivå 2;2022-08-19 (hanlid)

Available from: 2022-03-14 Created: 2022-03-14 Last updated: 2022-08-19Bibliographically approved
Rahimdel, M. J. & Ghodrati, B. (2022). Remaining useful Life Improvement for the Mining Railcars under the Operational Conditions. International Journal of Mining, Reclamation and Environment, 36(1), 46-67
Open this publication in new window or tab >>Remaining useful Life Improvement for the Mining Railcars under the Operational Conditions
2022 (English)In: International Journal of Mining, Reclamation and Environment, ISSN 1748-0930, E-ISSN 1748-0949, Vol. 36, no 1, p. 46-67Article in journal (Refereed) Published
Abstract [en]

The large tonnage mines use railway transportation as a system for mineral transportation. The rolling stock health condition study and improvement not only reduce the lifecycle cost of the assets but also ensures safe, reliable, punctual, and efficient transportation. The remaining useful life estimation is an efficient approach to condition-based maintenance, prognostics, and health management. This paper aims to predict the remaining life of a mining rolling stocks in the presence of operational environmental effects. In this study, the operation and failure data were obtained from Malmbana, LKAB, Sweden, a Swedish Railway Company, considering the effective operational factors. The failure behaviour of the railcar was evaluated and then the proportional hazard model was used to estimate the conditional reliability functions and accordingly the remaining useful life at the various initial survival time. Finally, the reliability-based time interval is applied to plan the maintenance operations. Results of this study show that the operator’s skill level and the maintenance quality had a significant influence on the reliability performance. By considering the proposed PM plan according to the desired reliability level, the remaining lifetime of the rolling stock will be improved by 78.10%, on average.

Place, publisher, year, edition, pages
Taylor & Francis, 2022
Keywords
Rolling stock, remaining useful life, proportional hazard model, preventive maintenance, lkab
National Category
Other Civil Engineering
Research subject
Operation and Maintenance
Identifiers
urn:nbn:se:ltu:diva-86529 (URN)10.1080/17480930.2021.1953316 (DOI)000680330700001 ()2-s2.0-85111904661 (Scopus ID)
Funder
Luleå Railway Research Centre (JVTC)
Note

Validerad;2022;Nivå 2;2022-03-07 (sofila);

Funder: CAMM (Centre of Advanced Mining & Metallurgy)

Available from: 2021-08-06 Created: 2021-08-06 Last updated: 2022-07-04Bibliographically approved
Allahkarami, Z., Sayadi, A. R. & Ghodrati, B. (2021). Identifying the mixed effects of unobserved and observed risk factors on the reliability of mining hauling system. International Journal of Systems Assurance Engineering and Management, 12(2), 281-289
Open this publication in new window or tab >>Identifying the mixed effects of unobserved and observed risk factors on the reliability of mining hauling system
2021 (English)In: International Journal of Systems Assurance Engineering and Management, ISSN 0975-6809, E-ISSN 0976-4348, Vol. 12, no 2, p. 281-289Article in journal (Refereed) Published
Abstract [en]

Reliability is widely used as a performance indicator of mining equipment to achieve a cost-effective maintenance plan. Reliability is a function of time as well as environmental and operational factors. Applying an adequate model by taking into account the mentioned factors is vital to ensure an accurate estimation of reliability characteristics. The aim of this study is to investigate the application of mixed frailty model to describe both observed and unobserved heterogeneity in reliability analysis of mining equipment. The capability of the model is assessed using field data from a fleet of dump trucks in an open-pit mine. The results indicate that the proposed model is superior to the traditional Cox model when data are heterogeneous. The results also show that the operator's skill and road conditions have a significant effect on the reliability of dump trucks.

Place, publisher, year, edition, pages
Springer, 2021
Keywords
Reliability, Hazard, Frailty, Dump truck, Mixed effects model, Unobserved risk factors
National Category
Other Civil Engineering
Research subject
Operation and Maintenance
Identifiers
urn:nbn:se:ltu:diva-83490 (URN)10.1007/s13198-021-01073-3 (DOI)000625598500002 ()2-s2.0-85102291916 (Scopus ID)
Note

Validerad;2021;Nivå 2;2021-04-06 (alebob)

Available from: 2021-04-06 Created: 2021-04-06 Last updated: 2021-05-26Bibliographically approved
Rahimdel, M. J. & Ghodrati, B. (2021). Risk Prioritization for Failure Modes in Mining Railcars. Sustainability, 13(11), Article ID 6195.
Open this publication in new window or tab >>Risk Prioritization for Failure Modes in Mining Railcars
2021 (English)In: Sustainability, E-ISSN 2071-1050, Vol. 13, no 11, article id 6195Article in journal (Refereed) Published
Abstract [en]

Railway transportation systems are generally used to transport minerals from large-scale mines. Any failure in the railcar components may cause delays or even catastrophic derailment accidents. Failure mode and effect analysis (FMEA) is an effective tool for the risk assessment of mechanical systems. This method is an appropriate approach to identify the critical failure modes and provide proper control measures to reduce the level of risk. This research aims to propose an approach to identify and prioritize the failure modes based on their importance degree. To achieve this, the analytical hierarchy process (AHP) is used along with the FMEA. To compensate for the scarcities of the conventional FMEA in using the linguistic variables, the proposed approach is developed under the fuzzy environment. The proposed approach was applied in a case study, a rolling stock operated in an iron ore mine located in Sweden. The results of this study are helpful to identify not only the most important failure modes but also the most serious and critical ones.

Place, publisher, year, edition, pages
MDPI, 2021
Keywords
mineral transportation, rolling stock, FMEA, AHP
National Category
Other Civil Engineering
Research subject
Operation and Maintenance
Identifiers
urn:nbn:se:ltu:diva-85878 (URN)10.3390/su13116195 (DOI)000660722200001 ()2-s2.0-85107851167 (Scopus ID)
Note

Validerad;2021;Nivå 2;2021-06-22 (johcin)

Available from: 2021-06-22 Created: 2021-06-22 Last updated: 2022-02-10Bibliographically approved
Rahimdel, M. J., Ataei, M. & Ghodrati, B. (2020). Modeling and Simulation Approaches for Reliability Analysis of Drilling Machines. Journal of The Institution of Engineers (India): Series C, 101, 125-133
Open this publication in new window or tab >>Modeling and Simulation Approaches for Reliability Analysis of Drilling Machines
2020 (English)In: Journal of The Institution of Engineers (India): Series C, ISSN 2250-0545, Vol. 101, p. 125-133Article in journal (Refereed) Published
Abstract [en]

Drilling, as the initial stage of exploitation in open-pit mining, has a significant effect on subsequent mining stages. Any failure in a drilling machine stops the drilling operation and, as a result, all following operational phases come to a halt. The drilling system is the most important part of the drilling operation. This study selected two new rotary-type drilling machines (A and B) in Sarcheshmeh Copper Mine in Iran as a case study to perform a reliability and availability analysis of their drilling systems. The drilling system was divided into three independent subsystems; drill string, rotary head, and mast. The reliability modeling used a reliability block diagram and Monte Carlo simulation. Reliability and availability were evaluated, and the importance of each subsystem estimated. A preventive maintenance schedule was proposed using weighed reliability allocation to achieve the reliability target. The results show the mast is the most reliable subsystem. Importance measure analysis indicates the drill string and rotary head are the most critical subsystems of machines A and B, respectively. Finally, under the proposed maintenance policy, the reliability of the drilling systems of machines A and B is improved.

Place, publisher, year, edition, pages
Springer, 2020
Keywords
Rotary drilling machine, Drilling system, Reliability, Monte Carlo simulation, Maintenance
National Category
Other Civil Engineering
Research subject
Operation and Maintenance
Identifiers
urn:nbn:se:ltu:diva-78331 (URN)10.1007/s40032-019-00533-x (DOI)2-s2.0-85072022563 (Scopus ID)
Note

Validerad;2020;Nivå 1;2020-04-03 (johcin)

Available from: 2020-04-03 Created: 2020-04-03 Last updated: 2020-08-26Bibliographically approved
Rahimde, M. J., Ghodrati, B. & Taghizadeh Vahed, A. (2020). Prediction of Mining Railcar Remaining Useful Life. In: Erkan Topal (Ed.), Proceedings of the 28th International Symposium on Mine Planning and Equipment Selection - MPES 2019: . Paper presented at 28th International Symposium on Mine Planning and Equipment Selection (MPES 2019), Perth, Australia, December 2-4, 2019 (pp. 281-288). Springer
Open this publication in new window or tab >>Prediction of Mining Railcar Remaining Useful Life
2020 (English)In: Proceedings of the 28th International Symposium on Mine Planning and Equipment Selection - MPES 2019 / [ed] Erkan Topal, Springer, 2020, p. 281-288Conference paper, Published paper (Refereed)
Abstract [en]

Railcar or Rolling stock that is referring to all vehicles moving on railway, is one of the most important component of the rail transport system. In-operation failures of the railcar results delays in transportation and therefore predicting the remaining useful life (RUL) and accordingly considering the preventive maintenance activities are essential. The RUL estimation is a key factor in predictive maintenance that has an influence on the maintenance scheduling, spare parts prediction and also the operational performance of the assets. This paper aims to model and analyze the RUL of railcars at LKAB, a Swedish Mining Company. To achieve this goal, first the failure behavior of the critical subsystems was analyzed and discussed. Then, with considering the effective operational factors (covariates), proportional hazard model (PHM) is applied to calculate the reliability functions. In this concept, RUL of the railcars can be obtained and discussed at the various initial survival times. 

Place, publisher, year, edition, pages
Springer, 2020
Series
Springer Series in Geomechanics and Geoengineering, ISSN 1866-8755, E-ISSN 1866-8763
Keywords
Rolling stock, Failure behavior, PHM, RUL
National Category
Reliability and Maintenance
Research subject
Operation and Maintenance
Identifiers
urn:nbn:se:ltu:diva-85871 (URN)10.1007/978-3-030-33954-8_35 (DOI)2-s2.0-85089316866 (Scopus ID)
Conference
28th International Symposium on Mine Planning and Equipment Selection (MPES 2019), Perth, Australia, December 2-4, 2019
Note

ISBN för värdpublikation: 978-3-030-33953-1; 978-3-030-33954-8

Available from: 2021-06-22 Created: 2021-06-22 Last updated: 2021-06-22Bibliographically approved
Hosseini Yazdi, M., Behzad, M., Ghodrati, B. & Khodaygan, S. (2020). Prognostic of rolling element bearings based on early-stage developing faults. International Journal of COMADEM, 23(1), 55-60
Open this publication in new window or tab >>Prognostic of rolling element bearings based on early-stage developing faults
2020 (English)In: International Journal of COMADEM, ISSN 1363-7681, Vol. 23, no 1, p. 55-60Article in journal (Refereed) Published
Abstract [en]

Rolling-element bearing (REB) failure is one of the general damages in rotating machinery. In this manner, the correct prediction of remaining useful life (RUL) of REB is a crucial challenge to move forward the unwavering quality of the machines. One of the main difficulties in implementing data-driven methods for RUL prediction is to choose proper features that represent real damage progression. In this article, by using the outcomes of frequency analysis through the Envelope method, the initiated/existed defects on the ball bearings are identified. Also, new features based on developing faults of ball bearings is recommended to estimate RUL. Early-stage faults in ball bearings usually include inner race, outer race, ball and cage failing. These features represent the sharing of each failure mode in failure. By calculating the severity of any failure mode, the contribution of each mode can be considered as the input to an artificial neural network. Also, the wavelet transform is used to choose an appropriate frequency band for filtering the vibration signal. The laboratory data of the ball bearing accelerated life (PROGNOSTIA) are used to confirm the method. To random changes reduction in recorded vibration data, which is primary in real-life experiments, a pre-processing calculation is connected to the raw data. The results obtained by using new features shows a more accurate estimation of the bearings' RUL and enhanced prediction capability of the proposed method. Also, results indicate that if the contribution of each failure mode is considered as the input of the neural network, then RUL is predicted more precisely.

Place, publisher, year, edition, pages
England: COMADEM International, 2020
Keywords
Prognostic, Rolling element bearing, Vibration
National Category
Other Civil Engineering
Research subject
Operation and Maintenance
Identifiers
urn:nbn:se:ltu:diva-80387 (URN)2-s2.0-85088894342 (Scopus ID)
Note

Validerad;2020;Nivå 1;2020-08-18 (alebob)

Available from: 2020-08-12 Created: 2020-08-12 Last updated: 2020-08-18Bibliographically approved
Heydari, S., Hoseinie, S. H., Ghodrati, B. & Kumar, U. (2020). Resilience measurement of longwall machinery. Rudarsko-Geološko-Naftni Zbornik, 35(3), 39-44
Open this publication in new window or tab >>Resilience measurement of longwall machinery
2020 (English)In: Rudarsko-Geološko-Naftni Zbornik, ISSN 0353-4529, E-ISSN 1849-0409, Vol. 35, no 3, p. 39-44Article in journal (Refereed) Published
Abstract [en]

This paper attempts to apply the resilience concept to the mining sector, especially to mining machinery and productionsystems. The quantitative analysis method using the linear recovery function has been applied. As the core part of theproposed method, it is assumed that in the mining machinery fleet, the performance function falls to a “zero” value immediatelyafter the occurrence of a failure. Therefore, the resilience calculation process runs through the concept of timeto repair and machine maintainability. As a case study for the proposed concept, the operation and failure data of thedrum shearer machine in Parvadeh longwall mine in Iran is applied. The data pertains to a coal cutting operation in awhole longwall panel over the period of two years. In total, the calculations encompass over 2600 hours of actual operationand 171.8 hours of repair time, which reveals that the studied shearer has a resilience of 96.7 percent. Along with thecase study results, it is confirmed by this paper that resilience as a developing concept could be adequately applied to coalmining systems as a support measure for production assurance and reliability.

Place, publisher, year, edition, pages
Croatia: Faculty of Mining, Geology and Petroleum Engineering, University of Zagreb, 2020
Keywords
coal, drum shearer, time to repair, performance function
National Category
Other Civil Engineering
Research subject
Operation and Maintenance
Identifiers
urn:nbn:se:ltu:diva-80386 (URN)10.17794/rgn.2020.3.4 (DOI)000552105300004 ()2-s2.0-85088317019 (Scopus ID)
Note

Validerad;2020;Nivå 2;2020-08-18 (alebob)

Available from: 2020-08-12 Created: 2020-08-12 Last updated: 2021-04-16Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-1377-8180

Search in DiVA

Show all publications