摘要
基于尺度相关的应变梯度塑性SG理论,对含孔洞的球形体胞模型进行了解析分析,得到了在基体梯度塑性环境下球形孔洞的演化规律,给出了弹塑性孔洞材料的宏观屈服面方程。与现有的基于尺度无关塑性理论的Gurson模型相比,该模型考虑了基体材料的特征长度l与孔洞半径α之比λ(λ=l/α)对多孔材料宏观屈服面和孔洞演化规律的影响。当不计基体材料的塑性梯度效应和硬化效应时,该模型能退化到经典的Gurson模型。
Based on approximate theoretical analyses on a representative spherical cell containing
a spherical microvoid, the influences of matrix materials' microscopic size on the macroscopic constitu-
tive potential theory of porous material and microvoid growth have been investigated in detail. By as-
suming that the plastic deformation behavior of matrix materials follows the strain gradient (SG) plastic
theory proposed by Fleck and Hutchinson (1997), the ratio (λ=l/α) of the intrinsic characteristic
length l of marix matrials to the microvoid radius α is introduced into the plastic constitutive potential
and the void growth law. The present results indicate that, when the radius α of microvoids is compa-
rable with the intrinsic characteristic length l of the matrix materials, the influence of microscopic size
effect on both the constitutive potential and the microvoid evolution predicted cannot be ignored. And
when the void radius α is much lager than the intrinsic characteristic length l of matrix materials, the
present model can retrogress automatically to the improved Gurson model considering the strain harden-
ing effect of matrix materials.
出处
《固体力学学报》
CAS
CSCD
北大核心
2003年第2期137-147,共11页
Chinese Journal of Solid Mechanics
基金
国家自然科学基金(A10102006)
教育部重点教改项目(282B11021)资助