Normal stresses at the tire-soil interface in yielding soils
Freitag, Dean R., 1926-; Green, A. J. (Andrew J.); Murphy, N. R. (Newell R.)
Miscellaneous PaperIntroduction: The U.S. Army Engineer Waterways Experiment Station at Vicksburg, Mississippi, is conducting systematic studies that will provide information on factors which influence vehicle mobility in deformable soils. The ultimate purpose of these studies is to develop rational means of designing military vehicles that will provide specified levels of performance in off-road conditions. A study of the stresses at the interface of a moving pneumatic tire and the medium upon which it travels is one such study. A pilot study to determine the distribution of stresses under pneumatic tires on an unyielding surface was conducted in the fall of 1961, and the results were presented at the 41st Annual Meeting of the Highway Research Board. Following this study, an extensive program was initiated to investigate and evaluate the factors that influence magnitude and distribution of the normal stresses between a pneumatic tire and deformable soils. While the objective of these studies is primarily military, the results will be applicable in many other fields. For instance, the development of knowledge pertaining to the stresses and strains or deformation at the tire-soil interface is important to the agricultural researcher who tries to minimize the compaction effect of pneumatic tires, and to the construction engineer who in many instances must depend upon the kneading action of pneumatic tires to help compact a fill or subgrade material. This paper describes the results of tests made to measure the distribution of stresses at the tire-soil interface under some representative test conditions. Two soils, a sand and a clay, carefully placed in a test pit, were used in the program. Each soil was tested at three different levels of strength. Only one tire at one test load was employed, but stresses were measured at several different inflation pressures. Tests were conducted with the wheel powered and with it towed.
U.S. Army Engineer Waterways Experiment StationEngineer Research and Development Center (U.S.)
Tire-soil interaction; Tire-soil interface; Soils; Soil mechanics; Soil compaction; Strains; Stresses; Mobility; Trafficability
Miscellaneous paper (U.S. Army Engineer Waterways Experiment Station) ; no. 4-629.
Approved for public release; distribution is unlimited.