A SIMPLER TEST FACILITY FOR LABORATORY WHEEL-TERRAIN EVALUATION OF 1/7ET CLAY

摘要

Conventional laboratory experiments to evaluate the wheel-terrain system have normally utilised a large soil bin and an instrumented moving wheel. This approach has necessitated a complex and expensive wheel frame and a large soil bin. The uniform preparation of the soil in the bin becomes more problematical as the bin size increases. When wet clay soils as found in the U.K. are used, the problems of uniform bin preparation and subsequent drying out of the soil during an extensive testing program are almost insurmountable. The test facility used comprised a wheel mounted in a fixed rigid frame. The soil was contained in a comparatively small bin mounted on a tracks The soil bin or trolley was moved into the wheel resulting in forced sinkage of the wheel into the soil. As both the soil bin and the test wheel were driven by separate motors the relative wheel speed and slip condition could be predetermined. By inclining the soil bin slightly, forced increasing sinkage occurred. Measurements made were the vertical and horizontal reaction on the wheel axle, the torque input to the wheel to maintain the rate of slip with increasing sinkage, the wheel speed and the trolley speed. The design, fabrication, instrumentation and operation of the equipment to achieve the planned goals is described. An assessment is made of the productivity rate of the test facility and the manpower input required.