Reliability Analysis of Combine Harvesters

The estimation of required total operational width of combine harvesters beforehand, especially for relatively big farms, is so important in terms of both the timely and possible least cost operation. Determination of required total operational width is a little bit complicate due to the difficulties in estimation of lost time resulted from unplanned breakdowns.In the context of this study, reliability analyses of 14 combine harvesters with same made and model were made based on the breakdown records which contain time between failures. The historical data of time between failures were modeled according to Weibull Distribution with three parameters. A developed software, namely WEPTIBFES v 2.0 was used in parameter estimation. Additionally, the module of Monte-Carlo simulation was added into software to simulate the time between failures. As a result of the study, totally 2470 data from 14 combine harvesters for last 10 years were evaluated. The estimated time between failures were calculated for given sub-systems of combine harvester. Weibull distribution parameters, the estimation statistics of b that defines the shape of distribution were determined. Additionally, and the result of validation tests were performed according to Kolmogorov-Smirnov test procedure. The lowest and the highest estimated time between failure values for cutting bar/feeding mechanism and components of control system were 82.16 and 234.74 hours respectively, while actual values were 88.2 and 254.2 hours.

Anahtar Kelimeler:

Combine harvester, grain harvesting, reliability

Reliability Analysis of Combine Harvesters

ABSTRACT: The estimation of required total operational width of combine harvesters beforehand, especially for relatively big farms, is so important in terms of both the timely and possible least cost operation. Determination of required total operational width is a little bit complicate due to the difficulties in estimation of lost time resulted from unplanned breakdowns.In the context of this study, reliability analyses of 14 combine harvesters with same made and model were made based on the breakdown records which contain time between failures. The historical data of time between failures were modeled according to Weibull Distribution with three parameters. A developed software, namely WEPTIBFES v 2.0 was used in parameter estimation. Additionally, the module of Monte-Carlo simulation was added into software to simulate the time between failures. As a result of the study, totally 2470 data from 14 combine harvesters for last 10 years were evaluated. The estimated time between failures were calculated for given sub-systems of combine harvester. Weibull distribution parameters, the estimation statistics of b that defines the shape of distribution were determined. Additionally, and the result of validation tests were performed according to Kolmogorov-Smirnov test procedure. The lowest and the highest estimated time between failure values for cutting bar/feeding mechanism and components of control system were 82.16 and 234.74 hours respectively, while actual values were 88.2 and 254.2 hours.

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ASAE, (1994). ASAE Standards-Test and Reliability Guidelines, ASAE EP456. American Society of Agricultural Engineers. St. Joseph, MI. 49085-9659.
Anonymous, S. (2008). Tarım Alet ve Makine Sayıları (Numbers of Agricultural Tools and Machines). (URL: http://www.tuik.gov.tr/bitkiselapp /tarimalet.zul). Latest Access: 12 June 2010
Billinton R., R. N. Allan, (1992). Reliability Evaluation of Engineering Systems (Concepts and techniques). 453 pp. Plenum Press, New York, London.
Bohm M., (1993). Breakdowns in Agricultural Tractors. Agricultural Engineer, Autumn 1993, p. 79-83.
Calabro, S.R., (1962). Reliability Principles and Practises. 262 pp. McGraw-Hill Book Company, Inc.
Hunt, D. (1983). Farm Power and Machinery Management. Iowa State University Press, p. 352.
Kumar R., J. R. Gross, (1977). A Study of Combine Harvester Reliability. Transactions of the ASAE, 20(1):30-34.
Laine A., M. Jarvenpaa, (1998). Reduction of Machine Costs on Finnish Farms by Extending the Operating Life of Tractors and Combine Harvesters. International Conference on Agricultural Engineering. Part 1, pp.471-472. Oslo 24-27 August 1998.
Say, S.M., A. Işık, (1997). Tarım Makineleri İle Çalışmada Arızalanma Oranı ve Güvenilirlik Değerlerinin Belirlenmesi (Determination of Breakdowns Ratio and Reliability Values when working with Agricultural Machines). Tarımsal Mekanizasyon 17. Ulusal Kongresi Bildiri Kitabı (Book of Papers for 17th National Agricultural Mechanisation Congress): 130-137. 17-19 September, Tokat.
Say, S.M. (2001). Biçerdöverle Hasatta Biçerdöver Çalışma Güvenilirliğinin Belirlenmesi ve Park Planlaması Üzerinde Bir Araştırma (A Research Study on Determination of Harvester Reliability in Harvesting and Park Planning). Ç.Ü. FBE, Doctoral Thesis, 157 pages.
Tufts, R.A. (1985). Failure Cause, Frequency, and Repair for Forest Harvesting Equipment. Transaction of the ASAE 28 (4):1673-1677. Ward S.M., M.B. Cunney, P.B. McNulty, (1985). Repair Costs and Reliability of Silage Mechanisation Systems. Transaction of the ASAE 28 (3):722-725.
Weibull, W., (1951). A Statistical Distribution Functions of Wide Applicability. Journal of Applied Mechanics, 18:293-297.