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  • 101.
    Abeysekera, John
    et al.
    Luleå tekniska universitet.
    Barabash, V.
    Human factors of clothing and work-wear: a review1994In: Proceedings: Second International Congress on Physiological Anthropology : September 12 - 16, 1994, University of Kiel, Germany, Kiel: German Society of Physiological Anthropology , 1994, p. 137-142Conference paper (Refereed)
    Abstract [en]

    An extraordinarily large share of research carried out in the near past on clothing comfort has been in the area of thermal comfort. Accordingly standards, norms and guidelines on thermal requirements of work-wear have been developed. Through behavioural adjustments people have learned to achieve thermal comfort even if the work clothes have slight deficiencies in thermal characteristics. It is beyond doubt that the thermal characteristics need careful consideration in the manufacture of work clothes. At the same time one must be aware that other human factors can also influence the overall wearability of clothing. This paper reviews the wearability and comfort of the clothing and work-wear to provide better understanding of the priorities in user needs in work clothes which can help plan future research and the need for new standards

  • 102.
    Abeysekera, John
    et al.
    Luleå tekniska universitet.
    Bergquist, Karin
    The need for research on human factors regarding personal protective devices in the cold environment1996In: Performance of protective clothing / [ed] James S. Johnson; S.Z. Mansdorf, West Conshohocken, Pa: ASTM International, 1996, Vol. 5Conference paper (Refereed)
    Abstract [en]

    The human factors or wearability needs of personal protective devices (ppd) and clothing (ppc) worn in the cold environment become more important as they must compromise with, and be adapted to, the clothing worn for cold protection. The occupational risks among outdoor workers in the cold can be aggravated if the wearability demands of ppd are not met. Failure to adequately meet user needs in currently used ppd in the cold environment has resulted in discomfort, injury, non-use and performance decrement among outdoor workers, particularly in the extreme cold regions. A preliminary study consisting of a literature survey in popular data bases and questionnaire survey among users of ppd, were carried out to ascertain what studies have already been conducted in this area and whether a wearability problem really exists among users, respectively. The literature revealed some specific areas where wearability problems exist and some research carried out on methods of testing of ergonomic characteristics of ppd. The questionnaire among ppd users in the cold climate confirmed that the workers do confront many inadequacies in the use of ppd. A case study carried out on ergonomic demands of safety shoes in the cold climate among users, manufacturers and experts revealed a similar trend of demands and priorities in ergonomics of shoes among all three groups. From the findings of the preliminary study it can be concluded that human factors research in ppd and particularly ppd worn on body extremities, viz. safety helmets, shoes and gloves, for use in the cold environment, seem urgent. Some research needs in the development of methods of testing for ppd evaluation are suggested

  • 103.
    Abeysekera, John D.
    Luleå tekniska universitet.
    Thermal environment and subjective discomfort of glass-factory workers in Sri Lanka1981In: Journal of Human Ergology, ISSN 0300-8134, Vol. 10, no 2, p. 185-92Article in journal (Refereed)
  • 104.
    Abeysekera, John D.A.
    Luleå tekniska universitet.
    A comparative study of body size variability between people in industrialised countries and industrially developing countries, its impact on the use of imported goods1987In: Ergonomics in developing countries: international symposium : proceedings : Jakarta, Indonesia, 18-21 November 1985, Geneva: Arkansas Philological Association, 1987, p. 65-91Conference paper (Refereed)
  • 105.
    Abeysekera, John D.A.
    Luleå tekniska universitet.
    Ergonomic aspects of personal protective devices in industrially developing countries1989Doctoral thesis, comprehensive summary (Other academic)
  • 106.
    Abeysekera, John D.A.
    Luleå tekniska universitet.
    Ergonomics and technology transfer1990In: International Journal of Industrial Ergonomics, ISSN 0169-8141, E-ISSN 1872-8219, Vol. 5, no 2, p. 181-184Article in journal (Refereed)
  • 107. Abeysekera, John D.A.
    Ergonomics for effective collaboration1997In: African Newsletter on Occupational Health and Safety, ISSN 0788-4877, no 2, p. 27-Article in journal (Other academic)
  • 108.
    Abeysekera, John D.A.
    Luleå tekniska universitet.
    The Need for National and International Ergonomics Standards for Personal Protective Devices1989In: Advances in industrial ergonomics and safety 1: proceedings of the annual International Industrial Ergonomics and Safety Conference held in Cincinnati, Ohio, U.S.A., 5-9 June 1989 / [ed] Anil Mital, London: Taylor and Francis Group , 1989, p. 809-816Conference paper (Refereed)
  • 109.
    Abeysekera, John D.A.
    et al.
    Luleå tekniska universitet.
    Holmér, Ingvar
    National Institute for Working Life.
    Dupuis, Christer
    Heat transfer characteristics of industrial safety helmets1991In: Towards human work: solutions to problems in occupational health and safety, London: Taylor and Francis Group , 1991, p. 297-303Chapter in book (Other (popular science, discussion, etc.))
  • 110.
    Abeysekera, John D.A.
    et al.
    Luleå tekniska universitet.
    Khan, Z.
    Slipping and falling accidents on icy surfaces: a case study from northern Sweden1998In: Problems with cold work: proceedings from an international symposium held in Stockholm, Sweden, November 16-20, 1997 / [ed] Ingvar Holmér; Kalev Kuklane, Solna: Arbetslivsinstitutet , 1998, p. 201-204Conference paper (Refereed)
  • 111.
    Abeysekera, John D.A.
    et al.
    Luleå tekniska universitet.
    Liu, Xiaoxiong
    A Scandinavian perspective on human factors testing of personal protective devices1997In: Performance of protective clothing: sixth volume ; [papers presented at the Sixth International Symposium on the Performance of Protective Clothing: Emerging Protection Technologies held in Orlando, Florida on 18 - 19 June 1996] / [ed] Jeffrey O. Stull; Arthur D. Schwope, West Conshohocken, Pa: ASTM International, 1997, p. 283-292Conference paper (Refereed)
    Abstract [en]

    Testing for protection performance and human factors in personal protective devices (PPD) can be undertaken using a standardised methodology. The standardised methodology for performance testing is used for the certification of PPD. However, it is unfortunate that methods of testing for human factors and wearability of PPD are scarce, and even the methods that do exist are not always refined or standardised. In both hot and cold environments, thermal comfort is an important user need of PPD. To test the thermal characteristics of PPD, methods providing objective data are available, yet they are not always standardised. An exception exists for insulation testing of clothing, for which standardised methods have been developed. The fit of PPD is also a priority need among wearers. Clothing fit is often tested subjectively. The objective methods developed to test the fit of PPD and clothing again require refinement and standardisation. Wearability of PPD urgently requires the development and standardisation of both objective and subjective testing methods. This paper provides insights into some testing methods on human factors of PPD that have been particularly useful over the years.

  • 112.
    Abeysekera, John D.A.
    et al.
    Luleå tekniska universitet.
    Shahnavaz, Houshang
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    A brief guide to questionnaire design: with examples from ergonomics1985Report (Other academic)
  • 113.
    Abeysekera, John D.A.
    et al.
    Tekniska högskolan i Luleå, CEDC.
    Shahnavaz, Houshang
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    A head-model reconstruction based upon photogrammetric data from Sri Lankan adult males relevant to the design of headgear1989In: Journal of Human Ergology, ISSN 0300-8134, Vol. 18, no 2, p. 199-211Article in journal (Refereed)
    Abstract [en]

    Due to the large variability in heads and faces in one population, the standard anthropometric dimensions of the head, measured from anatomical landmarks alone, may not suffice for the design of fitting headgear, e.g., helmets. To provide adequate data of the shapes and contours of the head to the designer, appropriate head models sculptured using comprehensive head dimensions, must be developed. This paper describes (a) a procedure of collecting comprehensive anthropometric data of the head using a photogrammetric method and (b) a simple sculpturing technique to reconstruct a head model of the user population

  • 114.
    Abeysekera, John D.A.
    et al.
    Luleå University of Technology.
    Shahnavaz, Houshang
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Body size data of Sri Lankan workers and their variability with other populations in the world: its impact on the use of imported goods1987In: Journal of Human Ergology, ISSN 0300-8134, Vol. 16, no 2, p. 193-208Article in journal (Refereed)
  • 115.
    Abeysekera, John D.A.
    et al.
    Tekniska högskolan i Luleå, CEDC.
    Shahnavaz, Houshang
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Body size variability between people in developed and developing countries and its impact on the use of imported goods1989In: International Journal of Industrial Ergonomics, ISSN 0169-8141, E-ISSN 1872-8219, Vol. 4, no 2, p. 139-149Article in journal (Refereed)
    Abstract [en]

    The Industrially Developing Countries (IDC) today, to a great extent, depend on Industrialized Countries (IC) for the supply of most industrial goods. An attempt has been made to ascertain the degree of design incompatibility experienced by users of these imported goods due to differences in the body sizes of people in producer and user countries. A comparative study of variations in body sizes is made from data available in literature and from anthropometric surveys. The results reveal differences in almost every part of the human body. The need for reliable anthropometric data in respect of IDC is stressed. Urgent measures are required to introduce changes in equipment, particularly for the benefit of users in IDC.

  • 116.
    Abeysekera, John D.A.
    et al.
    Tekniska högskolan i Luleå, CEDC.
    Shahnavaz, Houshang
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Effect of the hot environment on man1988In: International Symposium on Work in a Hot Environment and Heat Related Disorders, Khartoum 27-31 Jan. 1988, 1988Conference paper (Other academic)
  • 117.
    Abeysekera, John D.A
    et al.
    Tekniska högskolan i Luleå, CEDC.
    Shahnavaz, Houshang
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Ergonomic evaluation of modified industrial safety helmets for use in tropical environments1988In: Ergonomics International 88: proceedings of the tenth congress of the International Ergonomics Association, 1-5 August 1988, Sydney, Australia / [ed] Austen S. Adams, London: Taylor and Francis Group , 1988, p. 212-214Conference paper (Refereed)
  • 118.
    Abeysekera, John D.A.
    et al.
    Tekniska högskolan i Luleå, CEDC.
    Shahnavaz, Houshang
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Ergonomics aspects of personal protective equipment: its use in industrially developing countries1988In: Journal of Human Ergology, ISSN 0300-8134, Vol. 17, no 1, p. 67-79Article in journal (Refereed)
  • 119.
    Abeysekera, John D.A.
    et al.
    Tekniska högskolan i Luleå, CEDC.
    Shahnavaz, Houshang
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Ergonomics assessment of selected dust respirators: their use in the tropics1987In: Applied Ergonomics, ISSN 0003-6870, E-ISSN 1872-9126, Vol. 18, no 4, p. 266-72Article in journal (Refereed)
    Abstract [en]

    The suitability and effectiveness of four different types of British made respirators were studied with respect to comfort, convenience and fit on wearers in Sri Lanka (a developing country). Objective and subjective assessments were made to evaluate the degree of discomfort and interferences to the use of senses. The study revealed that factors such as breathing resistance, work-rate and activity period affected the physiological responses. The weight of the respirator and the skin temperature had no direct relationship with the cardiovascular stress. Positive-pressure respirators that gave lower face temperatures than negative-pressure masks gave this type of respirator an additional advantage in hot environments. Respirators that restricted jaw movement affected the speech intelligibility of the wearer. Orinasal masks restricted vision more than the other types. The problem of fit was found negligible though head and face dimensions significantly differed between the British and the Sri Lankans. Subjective assessment correlated well with objective tests.

  • 120.
    Abeysekera, John D.A.
    et al.
    Tekniska högskolan i Luleå, CEDC.
    Shahnavaz, Houshang
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Ergonomics evaluation of modified industrial helmets for use in tropical environments1988In: Ergonomics, ISSN 0014-0139, E-ISSN 1366-5847, Vol. 31, no 9, p. 1317-1329Article in journal (Refereed)
    Abstract [en]

    Hotness, weight, fitting problems etc., have been found to be the chief causes of the unpopularity of industrial safety helmets in tropical environments in developing countries (DC). Some selected safety helmets manufactured in industrialized countries (IC) were modified to provide extra head ventilation and to reduce weight, in order to make them more acceptable to users in hot environments. The modified helmets were subjected to ergonomics evaluation both objectively and subjectively in the laboratory (in simulated tropical conditions) as well as in the field situation. There was evidence that white helmets had some advantages in comfort, viz. reduction of hotness, compared to the other colours, e.g. red, green etc., when worn in the presence of radiant heat in the laboratory. Ventilation holes provided at the top of the shell seemed to reduce the greenhouse effect within the helmet shell which therefore felt less uncomfortable than a fully covered helmet. Even with a small reduction of weight, such as 45 g in helmets weighing about 350g, the difference in weight was perceived by the wearers. In adapting helmets made in IC for use in tropical climates, head ventilation and low weight perception are important aspects in comfort which need to be considered. In addition to low cost, a harness material suitable for sweat absorption is required. Adjustability and sizing to fit 90% of the user population also needs to be considered in the design and manufacture of safety helmets for people in DC.

  • 121. Abeysekera, John D.A.
    et al.
    Shahnavaz, Houshang
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Ergonomics of technology transfer1987In: International Journal of Industrial Ergonomics, ISSN 0169-8141, E-ISSN 1872-8219, Vol. 1, no 4, p. 265-272Article in journal (Refereed)
    Abstract [en]

    It is beyond doubt that high technology has elevated the standards of living of mankind. The modern technology created and developed to a great extent by Western or developed societies is now in great demand in Eastern and developing societies who are trying to leap-frog towards advancement. But unfortunately, in the transfer of technology, both the giver and the receiver seem to make many mistakes. A technology transferred without considering the ethnic variables in the societies and differences in the climates, has found to cause problems to the acquirer. Due to the basic human factor differences such as sizes of people, physical environment, physical capacities and organizational and cultural differences, a technology which is unadapted has found to be inappropriate, harmful, hazardous and unsuccessful. In the areas of health, working conditions, production and finance, undesirable effects have resulted through haphazard technology transfer, For a successful transfer, it is therefore stressed that technology has to be adapted or modified taking into consideration the technological, anthropological and socio-economic factors of the acquiring population

  • 122.
    Abeysekera, John D.A.
    et al.
    Tekniska högskolan i Luleå, CEDC.
    Shahnavaz, Houshang
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Ergonomics problems in the use of personal protective wear in industrially developing countries1987In: Proccedings of the XIth World congress on the prevention of occupational accidents and diseases: Stockholm, Sweden, 24-29 May 1987, 1987, p. 422-424Conference paper (Refereed)
  • 123.
    Abeysekera, John D.A.
    et al.
    Luleå tekniska universitet.
    Shahnavaz, Houshang
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Thermal environment and man1986Report (Other academic)
  • 124. Abeysekera, John D.A.
    et al.
    Shahnavaz, Houshang
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Chapman, Larry J.
    Ergonomics in developing countries1990In: Advances in industrial ergonomics and safety 2: proceedings of the annual International Industrial Ergonomics and Safety Conference held in Montreal, Quebec, Canada, 10-13 June 1990 / [ed] Biman Das, Taylor and Francis Group , 1990, p. 771-778Conference paper (Refereed)
  • 125.
    Abeysekera, John
    et al.
    Luleå tekniska universitet.
    Gao, Chuansi
    Luleå tekniska universitet.
    The identification of factors in the systematic evaluation of slip prevention on icy surfaces2001In: International Journal of Industrial Ergonomics, ISSN 0169-8141, E-ISSN 1872-8219, Vol. 28, no 5, p. 303-313Article in journal (Refereed)
    Abstract [en]

    Slips and falls on icy roads often result in fractures or sprains and is a major problem in Nordic countries. Walking trials by 25 subjects wearing four types of winter shoes on five different icy walking surfaces provided subjective and objective measures of tendency to slip and number of slips, respectively. Since friction is a major determinant of a slip, the influence of material spread on icy surfaces, the surface temperatures and the shoe soling characteristics versus the Coefficient of Friction (COF) of the shoes were measured. Sand and gravel on icy roads had positive effects on improving COF. The study revealed that the aetiology of slips and falls is multi-faceted and attempts to solve the problem must adopt a systems approach. Perception of risk, aging, training, experience and postural balance are other factors to be considered in preventing slips and falls. Future research should concentrate on the degree of impact of each factor to the aetiology of slips and falls, which can help to decide priority action in preventing slips and falls.

  • 126.
    Abeysekera, John
    et al.
    Luleå tekniska universitet.
    Holmér, Ingvar
    National Institute for Working Life.
    Termiska egenskaper hos skyddshjälmar: förbättring, validering och standardisering av en mätmetod1997Report (Other academic)
  • 127.
    Abeysekera, John
    et al.
    Luleå tekniska universitet.
    Holmér, Ingvar
    National Institute for Working Life.
    Utveckling av metoder för provning och värdering av personlig skyddsutrustning med avseende på våt värmeavgivning1996Report (Other academic)
  • 128.
    Abeysekera, John
    et al.
    Luleå tekniska universitet.
    Holmér, Ingvar
    National Institute for Working Life.
    Liu, Xiaoxiong
    Gao, Chaunsi
    Wu, Zenhua
    Some design recommendations to improve comfort in helmets: a case study from China1996In: Journal of Human Ergology, ISSN 0300-8134, Vol. 25, no 2, p. 145-154Article in journal (Refereed)
    Abstract [en]

    Unless the basic user needs are satisfied in safety helmets, it is difficult to get workers to wear them habitually and for long periods. Hotness, weight and fitting problems are major wearability issues that require improvements. The enormous need for an optimally designed helmet in China prompted a case study on comfort aspects in helmets. The subjective impressions of the wearers of test helmets provided useful information for design changes to improve comfort. The heat transfer measurements through helmets indicated the need for ventilation openings to be provided on the shell of plastic helmets. Due to the advantage of low weight and good ventilation, it is recommended that cane helmets be further developed to improve protection, wearability and durability, and subsequently be produced in large scale

  • 129.
    Abeysekera, John
    et al.
    ndustrial Ergonomics, Work Science Academy (WSA), Linköping.
    Illankoon, Prasanna
    Work Science Academy (WSA), Kandana, Sri Lanka.
    The demands and benefits of ergonomics in Sri Lankan apparel industry2016In: Work: A journal of Prevention, Assesment and rehabilitation, ISSN 1051-9815, E-ISSN 1875-9270, Vol. 55, no 2, p. 255-261Article in journal (Refereed)
    Abstract [en]

    Apparel exports bring in sizeable foreign income to Sri Lanka. To protect and promote this industry is a paramount need. This can be carried out by applying Human Factors/Ergonomics (HFE) which has proved to control negative effects at work places. This paper reports a case study which describes the demands and benefits of HFE in MAS Holdings which owns a large share of the apparel industry in Sri Lanka.The study consisted of walk through observation survey, a questionnaire survey and ergonomic work place analysis followed by a training programme to selected employees in three companies.Positive responses to questionnaires revealed good ergonomic practices in the work places surveyed. Ergonomically unfit chairs and potential hazards e.g. exposure to noise and hot environment were detected. It is seen that MAS have introduced strategies originated by Toyota Production System viz. 5S, Kaizen, six sigma etc., which are in fact ergonomic methods. A progressive project MAS boast of viz. ‘MAS Operating System’ (MOS) empowers training and development to employees.MAS Holdings has adequately realized the benefits of applying HFE as evident by the number of awards received. Relevant companies were advised to take appropriate corrective measures to control the potential hazards.

  • 130.
    Abeysekera, John
    et al.
    Luleå tekniska universitet.
    Liu, Xiaoxiong
    Holmér, Ingvar
    National Institute for Working Life.
    A method to measure the total heat transfer through helmets: prerequisite to design thermally comfortable helmets1992In: Proceedings / Fourth Scandinavian Symposium on Protective Clothing against Chemicals and other Health Hazards (NOKOBETEF IV), Kittilä, Finland, 5-7 February [1992] / [ed] Helena Mäkinen, Vantaa: Institute of Occupational Health , 1992, p. 42-47Conference paper (Refereed)
  • 131.
    Abeysekera, John
    et al.
    Luleå tekniska universitet.
    Liu, Xiaoxiong
    Luleå tekniska universitet.
    Piamonte, D. Paul
    Luleå tekniska universitet.
    Body sizes and other human factors differences between Swedish and foreign students in Swedish universities1994In: Ergonomics for Quality Life: Proceedings of the Third Pan-Pacific Conference on Occupational Ergonomics, Seoul, Korea, 13-17 November 1994, PPCOE , 1994, p. 420-423Conference paper (Refereed)
    Abstract [en]

    Past studies have shown large differences in body size between people of Industrialized Countries (ICs) and Industrially Developing Countries (IDCs). These differences can have negative effects on the usage of technology which IDCs today acquire to a great extent from ICs. At the same time, the number of students from IDCs seeking education and training in universities in ICs is increasing. This paper reports on the impact of human factors differences particularly body size differences between foreign and local students on the use of university facilities, based on anthropometric and questionnaire surveys carried out on a small scale by foreign graduate students of Lulea University, Sweden. The study revealed large differences in body sizes between local and foreign students. The questionnaire survey of foreign students showed that there are other significant human factors differences such as the use of a foreign language, viz. Swedish which is unique to Scandinavia, and the exposure to long cold winters. Whether these differences in human factors influence the acquisition of knowledge or learning capacity of foreign students is worth further investigation.

  • 132.
    Abeysekera, John
    et al.
    Luleå tekniska universitet.
    Lönnroth, Emma-Christin
    Piamonte, Dominic Paul T
    Luleå tekniska universitet.
    Shahnavaz, Houshang
    Welcoming the millennium from a decade of growth and development in ergonomics education and promotion2001In: International Journal of Industrial Ergonomics, ISSN 0169-8141, E-ISSN 1872-8219, Vol. 27, no 6, p. 365-Article in journal (Other academic)
  • 133.
    Abeysekera, John
    et al.
    Luleå tekniska universitet.
    Shahnavaz, Houshang
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Adaptation to discomfort in personal protective devices: an example with safety helmets1990In: Ergonomics, ISSN 0014-0139, E-ISSN 1366-5847, Vol. 33, no 2, p. 137-145Article in journal (Refereed)
    Abstract [en]

    Discomfort in the use of personal protective devices (PPD) has been one of the chief causes of their non-use. A field trial using industrial helmets was carried out to ascertain whether by training and repeated wearing subjects could experience a significant adaptation to discomfort. Ten subjects took part in the trial in a tropical environment by wearing helmets repeatedly (6 h a day) for one month. Subjective evaluations of discomfort were made at the end of the 1st, 3rd, 5th, 14th and 30th day. It was revealed that complaints of discomfort, viz. hotness, heaviness, bad fit, etc., decreased markedly throughout the 30 day period. Though positive responses of adaptation to discomfort seem to reach an optimum towards 30 days, it is difficult to draw any conclusions on the optimum period of adaptation for each discomfort factor. In relation to inherent discomforts that are extremely difficult to overcome without compromising the protection efficiency of a PPD, the principle of adaptation seems to be a very important facet which has to be developed for an effective PPD programme.

  • 134. Abhale, P.B.
    et al.
    Guha, M
    Nurni, Viswanathan
    Ballal, N.B.
    Prediction of gas flow through layered burden prolies in blast furnace2006Conference paper (Refereed)
  • 135. Abhale, P.B.
    et al.
    Guha, M.
    Ramna, M.V.
    Nurni, Viswanathan
    Ballal, N.B.
    Prediction of cohesive zone in a blast furnace using wall pressure tap data: modelling appproach2008Conference paper (Refereed)
  • 136. Abhale, P.B.
    et al.
    Guna, M.
    Ramna, R.V.
    Nurni, Viswanathan
    Investigation of computational aspects in simulation of gas flow in blast furnace2009Conference paper (Refereed)
  • 137. Abhale, P.B.
    et al.
    Nurni, Viswanathan
    Ballal, N.B.
    Blast furnace modelling2005Conference paper (Refereed)
  • 138.
    Abhale, P.B.
    et al.
    Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology, Bombay.
    Nurni, Viswanathan
    Ballal, N.B.
    Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology, Bombay.
    Efficient simulation of gas flow in blast furnace2009In: Computers, Materials & Continua, ISSN 1546-2218, Vol. 10, no 2, p. 195-216Article in journal (Refereed)
    Abstract [en]

    Simulation of gas flow in a multilayered non-isothermal packed bed is useful for blast furnace operators in deciding appropriate charging strategy. While using an anisotropic form of Ergun equation to simulate gas flow through such systems, a new solution methodology for non-isothermal gas with varying density flowing through a layered burden has been proposed. This involves handling non-linearity due to gas density variation with pressure and temperature by solving for the square of pressure instead of pressure directly and handling the non-linearity due to vertical bar nu vertical bar term in the Ergun equation by solving linearized form of Ergun equation and updating vertical bar nu vertical bar iteratively. The proposed scheme is capable of predicting the effect of layer structure on gas flow with economy in number of grid points as well as computation time

  • 139. Abhale, P.B.
    et al.
    Nurni, Viswanathan
    Ballal, N.B.
    Efficient simulation of gas flow in blast furnace2008Conference paper (Refereed)
  • 140. Abhale, P.B.
    et al.
    Yadav, V.K.
    Nurni, Viswanathan
    Ballal, N.B.
    Investigation of mal-distribution in blast furnace aerodynamics using a three dimensional simulation model2010Conference paper (Refereed)
  • 141.
    Abhale, Prakash Bansi
    et al.
    Global R and D, ArcelorMittal, Kolkatta.
    Yadav, Vishal Kumar
    Department of Metallurgy and Materials Engineering (MTM), Katholieke Universiteit, Leuven.
    Nurni, Viswanathan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Ballal, Bharath Nidambur
    Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology, Bombay.
    Efficient computation of gas flow in blast furnace in 3-D2012In: 6th Int. Congress on the Science and Technology of Ironmaking 2012, ICSTI 2012: Including Proceedings from the 42nd Ironmaking and Raw Materials Seminar, and the 13th Brazilian Symp. on Iron Ore, 2012, Vol. 1, p. 722-732Conference paper (Refereed)
    Abstract [en]

    Blast furnace continues to occupy prominent place among iron making technologies as it accounts for more than 90% of the hot metal produced in the world. In India, as a part of initiative from Ministry of Steel, efforts are being made to develop offline as well as online models with an aim to improve blast furnace performance. As a part of this effort, offline comprehensive models simulating the internal state of an operating blast furnace are being developed. Such comprehensive models involve systematic integration of various sub-models for gas flow, solid flow, reaction kinetics, enthalpy balance etc. Unlike in many other systems, these sub-processes are highly interlinked in blast furnace and hence call for large number of iteration among the sub-models which ultimately results in significant computation time. Our efforts in integration of these sub-models have indicated that the gas flow is one of the important bottle necks in achieving faster computation. This has led to a development of new and efficient computation scheme to simulate the gas flow in 2-D [1]. This new scheme provided efficient way of handling complex burden profile in a blast furnace. This paper presents the extension of this 2-D gas flow model to 3-D. Further, the 3-D model has been used to investigate the asymmetry in gas flow which can arise from blanking the tuyeres, asymmetric fusion or cohesive zone or formation scabs or scaffolds in the furnace behavior

  • 142.
    Abid, Fahim
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Busatto, Tatiano
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Rönnberg, Sarah
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Intermodulation due to interaction of photovoltaic inverter and electric vehicle at supraharmonic range2016In: 2016 17th International Conference on Harmonics and Quality of Power, Piscataway. NJ, 2016, p. 685-690, article id 7783471Conference paper (Refereed)
    Abstract [en]

    Advent of power electronic switching is introducing more and more non-linear loads in the low voltage grid. Besides harmonic current generation in the frequency range below 2 kHz, these non-linear loads are also responsible for current emission in the range of 2 kHz to 150 kHz, commonly known as supraharmonic emission. Supraharmonic currents mainly flow between nearby appliances and heavily influence the overall emission of neighboring devices. This paper presents an analysis of supraharmonic interaction between a photovoltaic inverter and an electric vehicle. It has been noticed that intermodulation distortion arises as a result of interaction between different switching frequencies used by the devices. Later, additional household equipment were added to photovoltaic and electric vehicle to observe their effect on intermodulation distortion. All the measurements were conducted in a controlled laboratory environment imitating a domestic customer.

  • 143.
    Abid Musa, Miriam
    Luleå University of Technology. Sweco Rail AB.
    Sweco Rail handbok för avbrottsfri kraftförsörjning till Trafikverkets linjebundna signalanläggningar2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 144.
    Abiri, Olufunminiyi
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mechanics of Solid Materials.
    Non-local models in manufacturing simulations2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Ductile fracture presents challenges with respect to material modelling andnumerical simulations of localization. The strain and damage localization maybe unwanted as it indicates a failure in the process or, as in the case ofmachining and cutting, a wanted phenomenon to be controlled. The latterrequires a higher accuracy regarding the modelling of the underlying coupledplastic and fracturing/damage behaviour of the material, metal in the currentcontext as well as the stability and robustness of the simulation procedure.This aim of this work is to develop, evaluate and implement formulations thatcan efficiently and reliably handle localization problems in machiningsimulations. The focus is on non-local models. The non-local models extendthe standard continuum mechanics theory by using non-local continuumtheory in order to achieve mesh independent results when simulating fractureor shear localization.The non-local damage model is implemented and various formulations areevaluated in a Matlab™ based finite element code. The chosen algorithm wasthen implemented in commercial software. The implementations remedy themesh sensitivity problem and gives convergent solution for metal cuttingsimulations with reasonable cost. The length scale associated with the nonlocalmodels are in the current context considered as a numericalregularization parameter. The model has been applied in machiningsimulations and compared with measurements from industry.Keywords: Finite element simulation; Non-local damage; Plasticity; Machining

  • 145.
    Abiri, Olufunminiyi
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mechanics of Solid Materials.
    Simplifications of non-local damage models2014Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Ductile fracture presents challenges with respect to material modelling and numerical simulations of localization. The strain and damage localization may be unwanted as it indicates a failure in the process or, as in the case of machining and cutting, a wanted phenomenon to be controlled. The latter requires a higher accuracy regarding the modelling of the underlying coupled plastic and fracturing/damage behaviour of the material, metal in the current context as well as the robustness of the simulation procedure. The focus of this thesis is on efficient and reliable finite element solution of the localization problem through the non-local damage model. The non-local damage model extends the standard continuum mechanics theory by using non-local continuum theory in order to achieve mesh independent results when simulating fracture or shear localization. In this work, the non-local damage model and its various simplifications are evaluated in an in-house finite element code developed using Matlab™. The accuracy, robustness, efficiency and costs of the models are investigated and also compared to a general multi-length scale finite element formulation. A numerical study versus published data is used to demonstrate the validity of the model. The explicit non-local damage variant will be implemented in a commercial finite element code for use in machining simulation

  • 146.
    Abiri, Olufunminiyi
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mechanics of Solid Materials.
    Lindgren, Lars-Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mechanics of Solid Materials.
    Non-local damage models in manufacturing simulations2013Conference paper (Refereed)
    Abstract [en]

    Localisation of deformation is a problem in several manufacturing processes. Machining is an exception where it is a wanted feature. However, it is always a problem in finite element modelling of these processes due to mesh sensitivity of the computed results. The remedy is to incorporate a length scale into the numerical formulations in order to achieve convergent solutions. Different simplifications in the implementation of a non-local damage model are evaluated with respect to temporal and spatial discretisation to show the effect of different approximations on accuracy and convergence.

  • 147.
    Abiri, Olufunminiyi
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mechanics of Solid Materials.
    Lindgren, Lars-Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mechanics of Solid Materials.
    Non-local damage models in manufacturing simulations2015In: European journal of mechanics. A, Solids, ISSN 0997-7538, E-ISSN 1873-7285, Vol. 49, p. 548-560Article in journal (Refereed)
    Abstract [en]

    Localisation of deformation is a problem in several manufacturing processes. Machining is an exception where it is a wanted feature. However, it is always a problem in finite element modelling of these processes due to mesh sensitivity of the computed results. The remedy is to incorporate a length scale into the numerical formulations in order to achieve convergent solutions. Different simplifications in the implementation of a non-local damage model are evaluated with respect to temporal and spatial discretisation to show the effect of different approximations on accuracy and convergence.

  • 148.
    Abiri, Olufunminiyi
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mechanics of Solid Materials.
    Qin, Hao
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mechanics of Solid Materials.
    Lindgren, Lars-Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mechanics of Solid Materials.
    Comparison of Multiresolution Continuum Theory and Nonlocal Dame model for use in Simulation of Manufacutring Processes2016In: International Journal for Multiscale Computational Engineering, ISSN 1543-1649, Vol. 14, no 1, p. 81-94Article in journal (Refereed)
    Abstract [en]

    Modelling and simulation of manufacturing processes may require the capability to account for localization behavior, often associated with damage/fracture. It may be unwanted localization indicating a failure in the process or, as in the case of machining and cutting, a wanted phenomenon to be controlled. The latter requires a higher accuracy regarding the modelling of the underlying physics, as well as the robustness of the simulation procedure. Two different approaches for achieving mesh-independent solutions are compared in this paper. They are the multiresolution continuum theory (MRCT) and nonlocal damage model. The MRCT theory is a general multilength-scale finite element formulation, while the nonlocal damage model is a specialized method using a weighted averaging of softening internal variables over a spatial neighborhood of the material point. Both approaches result in a converged finite element solution of the localization problem upon mesh refinement. This study compares the accuracy and robustness of their numerical schemes in implicit finite element codes for the plane strain shear deformation test case. Final remarks concerning ease of implementation of the methods in commercial finite element packages are also given.

  • 149.
    Abiri, Olufunminiyi
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mechanics of Solid Materials. University of Johannesburg, South Africa.
    Svoboda, Ales
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mechanics of Solid Materials.
    Lindgren, Lars-Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mechanics of Solid Materials.
    Wedberg, Dan
    Controlling Thermal Softening Using Non-Local Temperature Field in Modelling2016In: Journal of Machining and Forming Technologies, ISSN 1947-4369, Vol. 8, no 1-2, p. 13-28Article in journal (Refereed)
    Abstract [en]

    One of the aims of this work is to show that thermal softening due to the reduced flow strength of a material with increasing temperature may cause chip serrations to form during machining. The other purpose, the main focus of the paper, is to demonstrate that a non-local temperature field can be used to control these serrations. The non-local temperature is a weighted average of the temperature field in the region surrounding an integration point. Its size is determined by a length scale. This length scale may be based on the physics of the process but is taken here as a regularization parameter.

  • 150.
    Abiri, Olufunminiyi
    et al.
    Institute of Intelligent Systems, University of Johannesburg.
    Wedberg, Dan
    AB Sandvik Coromant.
    Svoboda, Ales
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mechanics of Solid Materials.
    Lindgren, Lars-Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mechanics of Solid Materials.
    Non-Local Modelling of Strain Softening in Machining Simulations2017In: IOP Conference Series: Materials Science and Engineering, ISSN 1757-8981, E-ISSN 1757-899X, Vol. 225, article id 012053Article in journal (Refereed)
    Abstract [en]

    Non-local damage model for strain softening in a machining simulation is presented in this paper. The coupled damage-plasticity model consists of a physically based dislocation density model and a damage model driven by plastic straining in combination with the stress state. The predicted chip serration is highly consistent with the measurement results. 

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