Abstract:Based on gradient-dependent plasticity,the non-homogeneous porosity and void ratio in shear band after initiation of shear localization is investigated in the paper. In order to deduce the analytical solution on local porosity,a typical micro-element body in shear band is analyzed with the assumption that the local plastic shear strain is proportional to local plastic volumetric strain. The analytical results show that porosity,void ratio,increment of porosity,increment of void ratio,rate of porosity and rate of void ratio are non-homogeneous in shear band. In the center of the shear band extremely large voids exist and in the boundary of the shear band the void ratio approaches to the initial void ratio. In the strain softening process,the maximum porosity in shear band increases gradually. Rate of porosity apparently increases with decrement of shear stress rate. Moreover,influences of shear softening modulus and internal length parameter of void ratio are investigated. Smaller internal length parameter leads to larger void ratio gradient,and the internal length parameter has no influence on maximum void ratio in shear band. However,void ratio gradient and maximum void ratio are dependent on shear softening modulus.