Abstract
As a first step to apply a finite element method to the analysis of soil resistance problems in the field of agricultural machinery, an explicit boundary value problem was analyzed by the finite element method adopting the stiffness equation deduced from the constitutive equation taking account of the elastic-plastic transition, and the validity of this analysis was examined as follows.
1) A load-settlement problem, one of the most fundamental boundary-value problems, was adopted as an explicit problem. The settlement test of a rigid strip footing on the sand bed was first carried out as shown in Fig. 2. The load-settlement curve obtained from this test is shown by the solid line in Fig. 3.
2) The load-settlement problem under the same condition as the above-mentioned test was analyzed by the finite element method. The calculated load-settlement curve is shown by the dashed line in Fig. 3. Further, the deformed configuration, the state of principal stresses, the isobars of vertical stress and the plastic zone at the 10.5mm settlement are depicted in Figs. 5, 6, 7 and 8 respectively.
In Fig. 3 we see the good agreement between the experimental load-settlement curve and the theoretical one.
The finite element method introduced in this paper would provide the useful theoretical guide to the estimation of the deformation resistance of real soils.
