基于能量耗散的土体本构关系及其参数确定  

A MODEL OF SOIL CONSTITUTIVE RELATION BASED ON ENERGY DISSIPATION AND ITS PARA METERS DETERMINATION

作　　者：秦理曼[1] 迟世春[1] 林皋[1] 

机构地区：[1]大连理工大学土木水利学院及海岸与近海工程国家重点实验室,辽宁大连116024

出　　处：《岩石力学与工程学报》2005年第A02期5625-5633,共9页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(50479057)

摘　　要：从热力学基本理论出发,研究了土体受力变形过程中的能量耗散函数,据此构造了土的弹塑性模型。模型的屈服轨迹、塑性流动、硬化规律及弹性规律均可通过自由能函数和耗散增量函数推导得到。研究中区分塑性功与能量耗散,引出了储存塑性功的概念,定性地讨论模型参数的物理意义及其取值。并通过拟合三轴试验曲线,确定了模型参数;将计算的应力–应变曲线及体变曲线或孔压增长与试验结果比较,验证了模型的有效性。这种本构模型的构造方法掘弃了以德鲁克公设为基础的传统塑性理论,自动满足热力学定律,具有较为严密的理论基础。A model based on ideas of thermomechanics, the first and second laws of thermodynamics, is introduced to describe the elasto-plastic behavior of soil deformation, and the method of determining model parameters is provided, Once the forms of the free energy function and dissipation potential function have been specified, the corresponding yield surface, flow rule, hardening rule as well as the elasticity law are deduced in a systematic manner. The plastic work and dissipation energy are distinguished explicitly. Not all plastic work is dissipated, but some are stored and can be recovered under reversed plastic loading. The physical meaning and range of model parameters are discussed. The parameters can be determined by fitting the triaxial test curves, and the genetic algorithm is adopted by using obtained parameters, and a group of drained triaxial tests are computed, and compared with the experimental results to verify the validity of the model, The model automatically satisfies the laws of thermodynamics, and there is no need to invoke any other postulations.

关 键 词：土力学 塑性 本构方程 热力学 三轴试验 

分 类 号：TU441[建筑科学—岩土工程]