中文摘要：

基于变分渐近法建立具有周期性微结构的金属基复合材料（MMCs）细观力学模型及相应的增量方程,以准确预测其典型的热弹塑性行为和初始屈服面。利用细、宏观尺度比很小的特点,对单胞变分能量泛函变化进行渐近扩展,计算得到有效瞬时弹塑性刚度矩阵和热应力矩阵;利用迭代均质化及局域化技术模拟MMCs的非线性热弹塑性性能,并通过有限元技术实现相应的数值模型。算例分析表明：该模型能较好地预测MMCs的初始屈服面,并模拟热弹塑性耦合行为,研究成果为MMCs的进一步研究和实际应用提供了技术支撑。

英文摘要：

To accurately predict the typical thermoelastoplastic behavior and initial yield surface of metal matrix composites （MMCs）with periodic microstructures,a micromechanical model and corresponding increment equation were presented based on the variational asymptotic method.This model uses the characteristic of small ratio of micro scale to macro scale to asymptotic expand the unit-cell variational energy functional changes.The effective instanta-neous elastoplastic stiffness matrix and thermal stress matrix were calculated.The iterative homogenization and lo-calization technology were used to simulate the nonlinear thermoelastoplastic performance of MMCs.The corre-sponding calculation model was realized through finite element technology.The numerical example analysis shows that this model can well predict the initial yield surface of MMCs and simulate thermoelastoplastic coupling behav-ior,which can provide technical support for further study and practical application of MMCs.