The high-fidelity generalized method of cells (HFGMC) micromechanical analysis is employed for the prediction of microbuckling stresses of composite materials which are composed of elastic–viscoplastic constituents. The inelastic material behavior is represented by a unified viscoplasticity theory which can model non-proportional loading paths, namely it is capable of providing the effect of axial loading on the reduction of shear modulus which dominates the microbuckling. By applying an incremental procedure and in conjunction with the instantaneous stiffnesses of the viscoplastic material, an eigenvalue problem at each time step is established by the HFGMC micromechanical method, which is modified to include the buckling terms arising from the linearization of the nonlinear equations of equilibrium. These buckling terms are provided by HFGMC analysis which predicts the local stress field and the effective current tangent properties of the composite. The present approach is verified by comparison of its predictions with an exact solution that can be established in the special case of composites that consist of periodic viscoplastic layers. Applications are given for the prediction of the microbuckling stresses of bi-layered, continuously reinforced and aligned short-fiber viscoplastic composites. In addition, the microbuckling stresses of viscoplastic lattices and layered plates are presented.

高保真广义单元法 (HFGMC) 微力学分析用于预测由弹-粘塑性成分组成的复合材料的微屈曲应力。非弹性材料行为由统一的粘塑性理论表示，该理论可以模拟非比例加载路径，即它能够提供轴向加载对剪切模量降低的影响，而剪切模量在微屈曲中占主导地位。通过应用增量程序并结合粘塑性材料的瞬时刚度，每个时间步长的特征值问题由 HFGMC 微机械方法建立，该方法被修改为包括由平衡非线性方程线性化产生的屈曲项. 这些屈曲项由 HFGMC 分析提供，该分析可预测复合材料的局部应力场和有效电流切线特性。本方法通过将其预测与可以在由周期性粘塑性层组成的复合材料的特殊情况下建立的精确解进行比较来验证。给出了用于预测双层、连续增强和对齐的短纤维粘塑性复合材料的微屈曲应力的应用。此外，还介绍了粘塑性晶格和层状板的微屈曲应力。本方法通过将其预测与可以在由周期性粘塑性层组成的复合材料的特殊情况下建立的精确解进行比较来验证。给出了用于预测双层、连续增强和对齐的短纤维粘塑性复合材料的微屈曲应力的应用。此外，还介绍了粘塑性晶格和层状板的微屈曲应力。本方法通过将其预测与可以在由周期性粘塑性层组成的复合材料的特殊情况下建立的精确解进行比较来验证。给出了用于预测双层、连续增强和对齐的短纤维粘塑性复合材料的微屈曲应力的应用。此外，还介绍了粘塑性晶格和层状板的微屈曲应力。