土料非线性滞回本构模型的半解析半离散构造方法

Semi-analytical and semi-discrete procedure for constructing nonlinear hysteretic constitutive model of soils

通常的土体动力真非线性分析方法难以同时合理地拟合整个应变范围内实际的动剪切模量Ｇｓ及阻尼比 ｅｑ随应变γ的非线性变化规律。为了克服这一缺陷，本文对于含固定参数的解析类骨架方程及相应的滞回曲线构造准则加以修正，即在原本构模型中取定或引进两个随应变幅值而变化的参数，并根据实测到的经验曲线Ｇｓ－γ及 ｅｑ－γ直接推求这些参数的变化规律。具体分析表明：如此所建立的动态本构模型既简便可行，又符合实际。

The conventional truly nonlinear analyses, which take the analytical function with invariant parameters as skeleton curve, usually cannot agree well with the experimentally - obtained data. Modifications on these analytical-type soil models are made, in which two parameters varying with strain level are introduced, these parameters can be directly determined according to sample relations between shear modulus, damping factor and strain amplitude achieved from cyclic- loading tests of soils. Case studies show that the proposed procedure is, because of its semi- analytical and semi-discrete characteristics, both simple and practically reasonable.