摘要
从热力学基本理论出发,研究了海相软土受力变形过程中的能量耗散。研究中区分了海相软土中弹塑性变形引起的能量损失,与因土体内部胶结结构破坏引起的能量损失,引出了结构性胶结损伤耗能的概念。在Collins的热力学土体模型的基础上,针对其不能考虑土体结构性的不足加以改进,构造了海相软土的能量耗散函数。结构性土体弹塑性模型的屈服轨迹、塑性流动、硬化规律及弹性规律均可通过能量耗散函数推导得到。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,具有较为严密的数学和力学理论基础。将本文提出模型的计算结果与人工制备海相软土的三轴试验结果进行了对比,初步验证了模型的适应性与有效性。
The ideas of thermomechanics,the first and second laws of thermodynamics,was introduced to describe the energy dissipation of marine clay deformation.The energy dissipation due to deformation and cementation bonds’damage were distinguished explicitly.Not all energy was dissipated by elasto-plastic behavior,but some were for damage dissipative of cementation bonds between soil particles.Based on the thermomechanical model proposed by Collins,its shortage of considering soil structure was improved by proposing a new energy dissipation potential function.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 were deduced in a systematic manner.The construction method of this constitutive model abandons the traditional plastic theory based on Drucker’s postulate,and automatically satisfies the laws of thermodynamics,which has a rigorous theoretical basis of mathematics and mechanics.And the adaptability and validity of the model were verified preliminarily by comparing its calculated results with the triaxial test results of artificially marine clay.
作者
刘鹏
黄容聘
Peng Liu;Rongpin Huang(School of Civil Engineering,Nanjing Forestry University,Nanjing 210037,P.R.China;Jiangsu Province Key Laboratory of Soil and Water Conservation and Ecological Restoration,Nanjing 210037,P.R.China)
出处
《地下空间与工程学报》
CSCD
北大核心
2020年第4期1088-1095,共8页
Chinese Journal of Underground Space and Engineering
基金
国家自然科学基金(51809139,51578293)。
关键词
热力学
本构方程
结构性土体
弹塑性
胶结
thermomechanics
constitutive equations
structured soil
elastoplasticity
the cementation bond
