基于旋转运动硬化理论的修正剑桥模型的改进

修正剑桥模型是最早建立和得到广泛承认的经典土体弹塑性模型之一，但不能模拟应力路径转折时土体的应力-应变特性以及应力引起的各向异性。将旋转运动硬化理论引入到剑桥模型中，给出了椭圆屈服面的旋转运动硬化机制，在不增加任何模型参数的情况下，把等向硬化的修正剑桥模型扩展为旋转运动硬化模型。扩展的新模型既保留了单调加载时的等向硬化的特性，又能反映应力路径转折时土体的本构特性与应力诱发的各向异性，初步验证了模型的有效性。

A revised modified Cambridge model based on the theory of rotational kinematic hardening

The modified Cambridge model is one of the most popular elastoplastic models for soil, but it can not simulate the soil constitutive behavior during large stress reversals and the stress induced anisotropy as well. In this paper, the rotational kinematic hardening theory is incorporated into modified Cambridge model, and the rotational hardening mechanism of ellipse yield surface is presented. Then, a new modified Cambridge model is extended from isotropic to rotational kinematic hardening in a simple manner which avoids the introduction of complicated rules and new materials parameters. The new model not only preserves the behavior of the isotropic hardening model under monotonic loading conditions, but also can reflects the soil constitutive behavior during large stress reversals and the stress induced anisotropy, and its validation is given at last.