基于广义位势理论的接触面弹塑性本构模型

基于广义位势理论,把土与结构的接触面问题看作(σn,τ)空间上的二维问题,用两个线性无关的势函数梯度矢量表示两个塑性应变增量的分量dεnp,dγp组成的矢量,并用塑性状态方程取代传统的屈服面,建立了双重势面接触面弹塑性新模型。结合含砾粗砂与钢板接触面单剪试验以及单向压缩试验资料,说明模型参数的确定方法,其中采用抛物线和一阶指数衰减曲线拟合接触面先剪缩后剪胀的试验曲线,曲线参数有物理意义且拟合精度高,参数完全可以通过试验确定。结果表明,模型数学原理清晰,物理假设少,且具有一般性,能够反映接触面的剪胀特性以及准确模拟接触面的变形特性。

Elasto-plastic constitutive model of interface based on generalized potential theory

Based on the generalized potential theory,an elasto-plastic model of multi-potential surface for interface was created.In the model,the soil-structure interface problem was regarded as two-dimensional question in(σn,τ) field,and the vector composed by the plastic strain increment of dε np and dγ p was represented by gradient vectors of two linearly independent potential functions σn and τ,and the plastic state equations were used to replace the traditional field surface.The model parameters could be obtained by uniaxial compression tests and simple shear tests.The method was introduced,and using the parabola and damped exponential curves to simulate the dilatancy of interface,in which the parameters with definite physical meanings and the fitting results with high quality.It was shown that the model,based on a legible mathematical theory and a small quantity of physical hypothesis,could reflect the dilatancy of interface and well simulate the deformation characteristics of interface.