Physical properties effect on stress-strain behavior of wheat En Masse - Part II. Constitutive elastoplastic parameter dependence on initial bulk density and moisture content

The effect of physical properties, i.e., the initial bulk density and moisture content, on the stress-strain behavior of wheat en masse was studied for axial and isotropic compression loadings. The dependence of fourteen Lade elastoplastic constitutive model parameters on three initial bulk densities and two moisture contents were analyzed statistically. Moisture content mostly affected the elastic parameters, whereas the initial bulk density mainly affected the plastic expansive parameters. Neither bulk density nor moisture content had a significant effect on the plastic collapse parameters over the range of test conditions. Constitutive parameter values were linearly interpolated at an intermediate initial bulk density and moisture content to predict and compare stress-strain behavior of wheat. The χ² test validated the model prediction in axial and isotropic compression at a 0.05 level of significance.