PERFORMANCE OF SOILS UNDER TIRE LOADS. REPORT 6. EFFECTS OF TEST TECHNIQUES ON WHEEL PERFORMANCE.
Abstract
A study was made of the effects of various testing techniques on the performance of pneumatic tires operating in an air-dried desert sand and a nearly saturated fat clay. Tests employing both controlled-slip and controlled-pull techniques were conducted with single-wheel dynamometer carriages. The results are presented in the form of graphs with emphasis placed upon the pull-slip and torque-slip relations. For the conditions tested, wheel performance was found to be independent of testing techniques, with one exception; consistent differences were noted between the results of programmed-increasing- and programmed-decreasing-slip tests. However, this disagreement occurred only for a narrow range of slip (approximately -10 to +10%). Careful and complete analysis of a dynamic test system must be made to determine the forces that actually represent the wheel performance. A brief analysis of the horizontal forces acting on the test dynamometers is given to emphasize this point, particularly with regard to differences between pull-slip and drawbar pull-slip relations. It is shown that because of the inability always to attain a stable condition in controlled-pull tests, controlled-slip tests are better for defining pull-slip relations. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1967
- Accession Number
- AD0823500
Entities
People
- Newell R. Murphy Jr.