循环荷载作用下土的非线性应力应变模型

本文在伊万（Iwan）模型的基础上,提出了一个新的物理模型。新模型导出的应力-应变关系,骨架曲线的形状既可为加工硬化状,也可为加工软化状,且骨架曲线与滞回曲线的两个分枝可以相同,也可不同。而梅辛（Masing）型关系只是其中的一种特殊情况。根据该物理模型,对土在循环荷载作用下的剪应力-剪应变关系,提出了一个分析模型,目前常用的双曲线模型只是该分析模型的一个特例。最后还对读物理模型所代表的非线性系统在谐和外力作用下的稳态反应进行了讨论。

Nonlinear Stress-strain Models of Soils under Cyclic Loadings

In this paper a kind of new physical models is proposed on the basis of the Iwan models. In the stress-strain relationships derived from the new physical models the backbone curve may appear in the form of work-harden or work-soften and two branches of backbone and hysteresis curves are not necessarily the same. The masing type's relationships can be obtained from the formulations of the new models. According to the new physical models, an analytical model to describe the shear stress-shear strain relationships of soils under cyclic loadings is suggested and the hyperbolic model is only a particular case of such model. Finally, the steady-state response of the nonlinear system depicted by new physical models under harmonic force is discussed.