Many composites and their constituents exhibit strength difference (SD) effects. To reduce the computational cost associated to twoscale simulations, the theory of nonuniform transformation field analysis (NTFA, originally proposed by Michel and Suquet, 2003) is extended to consider a general case of SD effects in elastoplasticity, containing several well-known plasticity models like von Mises or Drucker and Prager as special cases. A space-time decomposition is done separately for volumetric and deviatoric inelastic strain fields, thus leading to two sets of plastic modes with different charateristics. Localization rules are deduced from superposition principles for the microscopic strain and stress fields, which are then homogenized to obtain the effective response. A coupled model governing the evolution of the resulting reduced variables is proposed based on some dissipative considerations. A convenient matrix formulation for an FE-based implementation is presented in detail. The proposed coupled model is shown to be exact for homogeneous cases and sufficiently accurate for three-dimensional heterogeneous microstructures. Finally, an efficient structural analysis is performed by using corresponding algorithmic consistent tangent operators.

许多复合材料及其成分表现出强度差异 (SD) 效应。为了减少与双尺度模拟相关的计算成本，非均匀变换场分析理论（NTFA，最初由 Michel 和 Suquet，2003 年提出）被扩展到考虑弹塑性中 SD 效应的一般情况，包含几个众所周知的塑性模型，如von Mises 或 Drucker 和 Prager 作为特例。对体积和偏非弹性应变场分别进行时空分解，从而导致两组具有不同特性的塑性模式。根据微观应变场和应力场的叠加原理推导出局部化规则，然后将其均质化以获得有效响应。基于一些耗散考虑，提出了一种控制所产生的减少变量演变的耦合模型。详细介绍了基于有限元实现的方便矩阵公式。所提出的耦合模型被证明对于均质情况是准确的，并且对于三维异质微结构也足够准确。最后，通过使用相应的算法一致切线算子进行有效的结构分析。