Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
권호 표지
DOI QR코드

DOI QR Code

Assessment of Slip Sinkage of an Off-Road Tracked Vehicle from Model Track Experiments

모형궤도시험을 통한 야지궤도차량의 슬립침하 평가

  • Baek, Sung-Ha (Dept. of Civil & Environmental Engrg., Gachon Univ.) ;
  • Shin, Gyu-Beom (Dept. of Civil & Environmental Engrg., Seoul National Univ.) ;
  • Chung, Choong-Ki (Dept. of Civil & Environmental Engrg., Seoul National Univ.)
  • 백성하 (가천대학교 토목환경공학과) ;
  • 신규범 (서울대학교 건설환경공학부) ;
  • 정충기 (서울대학교 건설환경공학부)
  • Received : 2018.04.24
  • Accepted : 2018.05.25
  • Published : 2018.06.30
Download PDF
⟨ Previous Next ⟩

Abstract

When a tracked vehicle travels off-road, shearing action and ground sinkage occur on the soil-track interface and severely affect tractive performance of the tracked vehicle. Especially, the ground sinkage, which is induced by vehicle's weight (hereinafter referred to as static sinkage) and longitudinal forces in the direction of travel producing slip (hereinafter referred to as slip sinkage), develops soil resistance, directly restricting the tractive performance of an off-road tracked vehicle. Thus, to assess the tractive performance of an off-road tracked vehicle, it is imperative to take both of static sinkage and slip sinkage into consideration. In this research, a series of model track experiments was conducted to investigate the slip sinkage which has not been clarified. Experiment results showed that the slip sinkage increased with increasing the slip ratio, but the increasing rate gradually decreased. Also, the slip sinkage was found to increase as relative density of soil decreased and imposed vertical load increased. From the experiment results, the normalized slip sinkage defined as slip sinkage to static sinkage calculated in the identical condition was investigated, and an empirical equation for the slip sinkage was developed in terms of slip ratio, which allows vehicle operators to predict the slip sinkage in a given soil and operating conditions.

차량의 엔진성능에 따라 구동성능이 결정되는 도로주행차량과 달리, 포장되지 않은 지반 위를 주행하는 야지궤도차량의 구동성능은 지반-궤도 접지면에서 발생하는 지반의 전단 및 침하현상에 의해 제한된다. 특히 차량의 중량에 의해 발생하는 정적침하 및 슬립에 의해 유발되는 슬립침하는 지반-궤도 접지면에서 지반저항력을 발현시켜 야지궤도 차량의 구동을 직접적으로 방해하는 요소로 작용한다. 따라서 야지궤도차량의 구동성능을 확보하기 위해서는 정적침하 및 슬립침하를 평가하고 제한할 필요가 있다. 본 연구에서는 야지궤도차량의 중량 및 구동지반의 특성이 슬립침하에 미치는 영향을 종합적으로 평가하기 위하여, 다양한 연직하중 및 지반조건에서 모형궤도시험을 수행하였다. 모형 시험 결과, 모든 시험조건에 대해 슬립율이 증가할수록 슬립침하가 증가했지만, 그 증가량은 점차 감소하는 것으로 나타났다. 또한 궤도시스템에 재하 된 상부 연직하중이 크고 모형지반의 상대밀도가 작을수록 슬립침하가 커지며 이에 따라 지반저항력도 증가하는 것으로 평가되었다. 추가적으로, 평가된 슬립침하를 각 시험조건 별로 산정된 정적침하로 정규화 시킨 뒤 이를 슬립율에 관한 함수로 나타내어 야지궤도차량의 침하량 및 지반저항력 산정 시 활용 가능하도록 하였다.

Keywords

References

  1. Baek, S.H., Shin, G.B., Kwon, O., and Chung, C.K. (2018), "Evaluation of Tractive Performance of an Underwater Tracked Vehicle based on Soil-track Interaction Theory", J. of the Korean Geotechnical Society, Vol.34, No.2, pp.43-54. https://doi.org/10.7843/KGS.2018.34.2.43
  2. Bekker, M.G. (1956), Theory of Land Locomotion, University of Michigan Press.
  3. Bekker, M.G. (1960), Off the Road Locomotion, University of Michigan Press.
  4. Bekker, M.G. (1969), Introduction to Terrain-Vehicle Systems, University of Michigan Press.
  5. Bowles, J.E. (1987), "Elastic Foundation Settlement on Sand Deposits", J. of Geotechnical Engineering, ASCE, Vol.113, No.8, pp.846-860. https://doi.org/10.1061/(ASCE)0733-9410(1987)113:8(846)
  6. Ding, L., Gao, H., Deng, Z., Nagatani, K., and Yoshida, K. (2011), "Experimental Study and Analysis on Driving Wheels' Performance for Planetary Exploration Rovers Moving in Deformable Soil", J. of Terramechanics, Vol.48, pp.27-45. https://doi.org/10.1016/j.jterra.2010.08.001
  7. Frost, J.D. and Park, J.Y. (2003), "A Critical Assessment of the Moist Tamping Technique", Geotechnical. Testing J., Vol.26, pp. 57-70.
  8. Grecenko, A. (2007), "Re-examined Principles of Thrust Generation by a Track on Soft Ground", J. of Terramechanics, Vol.44, No.1, pp.123-131. https://doi.org/10.1016/j.jterra.2006.04.002
  9. Hunt, R.E. (1986), Geotechnical Engineering Analysis and Evaluation, McGraw Hill Book Company.
  10. Iai, S. (1985), "Similitude for Shaking Table Tests on Soil-structure-fluid Model in 1g Gravitational Field", Soils and Foundation, Vol. 29, No.1, pp.105-118. https://doi.org/10.3208/sandf1972.29.105
  11. Kacigin, V.V. and Guskov, V.V., "The Basis of Tractor Performance Theory", J. of Terramechanics, Vol.5, No.3, pp.43-66.
  12. Kogure, K. (1976), "External Motion Resistance Caused by Rut Sinkage of a Tracked Vehicle", J. of Terramechanics, Vol.13, No.1, pp.1-14. https://doi.org/10.1016/0022-4898(76)90027-6
  13. Kogure, K., Ohira, Y., and Yamaguchi, H. (1983), "Prediction of Sinkage and Motion Resistance of a Tracked Vehicle Using Plate Penetration Test", J. of Terramechanics, Vol.20, No.3/4, pp.121-128. https://doi.org/10.1016/0022-4898(83)90043-5
  14. Ladd, R.S. (1978), "Preparing Test Specimens Using under Compaction", Geotechnical. Testing J., Vol.1, pp.16-23. https://doi.org/10.1520/GTJ10364J
  15. Lambe, T.W. and Whitman, R.V. (1979), Soil Mechanics, John Wiley & Sons.
  16. Liu, K., Ayers, P., Howard, H., and Anderson, A. (2010), "Lateral Slide Sinkage Tests for a Tire and a Track Shoe", J. of Terramechanics, Vol.47, pp.407-414. https://doi.org/10.1016/j.jterra.2010.05.003
  17. Lyasko, M. (2010), "Slip Sinkage Effect in Soil-vehicle Mechanics", J. of Terramechanics, Vol.47, pp.21-31. https://doi.org/10.1016/j.jterra.2009.08.005
  18. Park, Y.H. (1996), "Interaction of Soils-tracked Vehicle", PhD thesis, Department of Civil and Environmental Engineering, Seoul National University.
  19. Reece, A.R. (1964), "Problems of Soil-vehicle Mechareccenics", US Army Land Locomotion Lab, ATAC, No. 8479, Mich: Warren.
  20. Reece, A.R. (1965), "Principle of Soil Vehicle Mechanics", Proceeding Institute of Mechanical Engineers, Vol.180, Part 2A, London, pp. 45-61.
  21. Schmertmann, J.H., Hartman, J.P., and Brown, P.R. (1978), "Improved Strain Influence Factor Diagrams", Geotechnique, Vol.104, No.GT8, pp.1131-1135.
  22. Terzaghi, K. (1943), Theoretical Soil Mechanics, Wiley.
  23. WES (1994), Working Draft, Part Two, Road Chapter 9, Soils Trafficability. U.S. Army Corps of Engineers Waterways Experiment Station, Vicksburg.
  24. Wong, J.Y. (1989), Terramechanics and Off-Road Vehicle Engineering, Elsevier.
  25. Wong, J.Y. and Huang, W. (2006), "Wheels vs. Tracks - A Fundamental Evaluation from the Traction Perspective", J. of Terramechanics, Vol.43, No.1, pp.27-42. https://doi.org/10.1016/j.jterra.2004.08.003
  26. Yong, R., Fattah, E., and Skiadas, N. (1984), Vehicle Traction Mechanics, Elsevier.