In this paper, an elastoplastic-damage coupling constitutive model for unidirectional fiber-reinforced polymer matrix composites (UD FRPs) is presented, which both considers the plastic-hardening and damage-softening processes. Tension-compression asymmetry and shear strength increase due to transverse compression are observed under off-axis tensile/compressive tests of UD E-glass/YPH-200. Therefore, a four-parameter plastic yield criterion considering these two effects is proposed. Applying this model to predict the off-axis tensile/compressive responses of present tests provides good agreement with experimental curves. In addition, we give a novel definition of shear damage variable based on Puck failure theory and discuss it in detail. Further, we develop a four-parameter matrix failure criterion for UD FRPs and exactly predict the off-axis failure strength.

本文提出了一种单向纤维增强聚合物基复合材料（UD FRPs）的弹塑性-损伤耦合本构模型，该模型同时考虑了塑性硬化和损伤软化过程。在UD E-glass / YPH-200的离轴拉伸/压缩测试中，观察到由于横向压缩导致的拉伸压缩不对称和剪切强度增加。因此，提出了考虑这两个影响的四参数塑性屈服准则。应用该模型预测当前测试的离轴拉伸/压缩响应可与实验曲线很好地吻合。此外，我们基于Puck破坏理论给出了剪切损伤变量的新颖定义，并对其进行了详细讨论。进一步，