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Based on approximate theoretical analyses on atypieal spherical cell containing a sphericalmicrovoid,the influences of matrix materials’ microscopic scale on the macroscopic constitutive potential the-ory of porous material and microvoid growth have been investigated in detail.By assuming that the plastic de-formation behavior of matrix materials follows the strain gradient (SG) plastic theory involving the stretch androtation gradients,the ratio (λ=l/a) of the matrix materials’ intrinsic characteristic Length l to the micro-void radius a is introdnced into the plastic constitutive potential and the void grroth law.The present resultsindicate that,when the radius a of microvoids is comparable with the intrinsic characteristic length l of thematrix materials,the influence of microscopic size effect on neither the constitutive potential nor the micro-void evolution predicted can he ignored.And when the void radius a is much lager than the intrinsic charac-teristic length l of the matrix materials,the present model can retrogress automatically to the improved Gur-son model that takes into account the strain hardening effect of matrix materials.
Based on approximate theoretical analyzes on atypieal spherical cell containing a spherical microvoid, the influences of matrix materials’ microscopic scale on the macroscopic constitutive potential the-ory of porous material and microvoid growth have been investigated in detail. By assuming that the plastic de-formation behavior of matrix materials follows the strain gradient (SG) plastic theory involving the stretch and rotation gradients, the ratio (λ = l / a) of the matrix materials’ intrinsic characteristic length l to the micro-void radius a is introdnced into the plastic constitutive potential and the void grroth law.The present resultsindicate that, when the radius a of microvoids is comparable with the intrinsic characteristic length l of thematrix materials, the influence of microscopic size effect on neither the constitutive potential nor the micro-void evolution predicted can he ignored .And when the void radius a is much lager than the intrinsic charac-teristic length l of the matrix materials, the present model can retrogress automatically to the improved Gur-son model that takes into account the strain hardening effect of matrix materials.