Volume Change of Heterogeneous Quasi-brittle Materials in Uniaxial Compression

The volumetric strain was categorized into elastic and plastic parts. The former composed of axial and lateral strains is uniform and determined by Hooke’s law; however, the latter consisting of axial and lateral strains is a function of thickness of shear band determined by gradient-dependent plasticity by considering the heterogeneity of quasi-brittle materials. The non-uniform lateral strain due to the fact that shear band was formed in the middle of specimen was averaged within specimen to precisely assess the volumetric strain. Then, the analytical expression for volumetric strain was verified by comparison with two earlier experimental results for concrete and rock. Finally, a detailed parametric study was carried out to investigate effects of constitutive parameters (shear band thickness, elastic and softening moduli) and geometrical size of specimen(height and width of specimen) on the volume dilatancy.

The volumetric strain was categorized into elastic and plastic parts. The farmer camposed of axial and lateral strains is uniform and determined by Hooke＇s law ; however, the latter consisting of axial and lateral strains is a fuaction af thickness af shear band determined by grndieat-dependeat plasticity by cansidering the heterngeneity of quasi- brittle materials. The non- uniform lateral strain due to the fact that shear band was farmed in the middle of specimen was averaged within specimen to precisely assess the volumetric strain. Then, the analytical expression for volumetric strain was verified by comparison with two earlier experimental results for concrete and rack. Finally, a detailed parametric study was carried out to investigate effects of constitutive parameters （ shear band thickness, elastic and softening rnoduli ） and geometrical size of specimen（ height and width of specimen ） on the volume dilatancy.