偶应力/应变梯度弹塑性理论有限元实现

引入了偶应力弹塑性理论的增量形式,并提出了一种新的应变梯度理论,该理论引入了两个细观材料长度,结构较为简便.采用RCT9+RT9单元对软化材料的剪切带问题进行分析,该单元无多余零能模式且满足C0-1分片检验,即同时满足C1常曲率分片检验和C0线性应力分片检验.数值结果表明,利用传统弹塑性理论分析剪切带问题会出现显著的网格依赖性现象,而偶应力/应变梯度理论可以有效地避免这一问题,使计算结果收敛,此外,剪切带宽度随细观材料长度的减小而变窄.

Finite element methods in couple stress/strain gradient elasto-plasticity theory

The flow theory of couple stress gradient elasto-plasticity is derived and a new strain gradient theory is introduced,which includes only two length scales and has a simple structure.A RCT9+RT9 plane triangular element is applied to shear band problem of softening materials.This element has no spurious zero energy modes and passes the C0-1 patch test,namely passing the C1 constant curvature patch test and the C0 linear stress patch test simultaneously.Numerical results show that pathological mesh dependence...