1973 年 35 巻 1 号 p. 4-13
To improve the trafficability of farm use vehicle, the measurement of stress distribution under the driving devices is needed. Some kinds of method for finding the stress distribution, therefore, have been studied such as pressure cell transducer with strain gage on it. The motion and movement of soil under rigid wheel or rubber tire wheel have been observed in the perspex-sided soil bin test. Photoelasticity can be applicable to this kind of problem as far as the assumption that the soil is elastic can be useful.
In this paper, the author tried to see directly the stress distribution under rigid wheel by the application of photoelasticity experimental method.
The results ware discussed from the theoretical point and compared with the calculated results obtained by the finite element method.
New procedure to determine the unknowh values was introduced, in which the stress distribution under rigid wheel and various values were determined by obtaining the center of gravity of the closed area in the stress distribution curve. Various unknown values such as θ, e, R, F and a in Fig. 1(c) were obtained from the stress distibution of photoelastic material under rigid wheel by taking the isochromatic line diagram.
Those values obtained in this method were valid with the ones determined from the theoretical approach. New procedure in determining the various unknown factors such as θ, e, F and R etc. are valid even though the photoelasticity can only be applied to the problem of elasticity.
The author wishes, therefore, further investigation should be taken place by repeating more experiments to reconfirm this new procedure.