摘要
传统的黏塑性统一本构模型只能用于金属类材料的本构分析,而不适用于混凝土的本构分析。基于此,以不可逆热力学理论为基础,选定了涉及混合硬化参量的Helmholtz自由能函数,推导出混凝土的黏塑性损伤耦合本构模型。通过对混凝土硬化模型的分析,构造了含运动硬化和等向硬化内变量的非相关流动势函数,又推导出流动方程以及内变量演化方程。所建模型对混凝土试验曲线的数值模拟显示,其能够正确描述混凝土的率相关性、非弹性体积膨胀特性、加载过程的软硬化特性以及由断裂和损伤引起的应力软化现象。
The tyaditional unified viscoplasticity constitutive model is only applied for the constitutive analysis of metallic materials. A coupled viscoplasticity damage constitutive model for concrete is developed within the framework of irreversible thermodynamics; and an expression for the Helmholtz free energy function involving the state variables of mix hardening is given. The hardening model of concrete is analyzed; and the flow equation and the evolution equations of the state variables are derived from a non-associated flow potential function including the state variables of kinematic hardening and isotropic hardening. The results of numerical simulation show that the represented model can reproduce the strain-rate sensitive characteristic, inelastic volume dilatancy, softenting-hardening under loading; and strain-softening induced by damages and fractures.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2008年第11期2961-2966,共6页
Rock and Soil Mechanics
基金
国家自然科学基金重大计划项目(No.90410012)
关键词
混凝土
不可逆热力学
等向硬化
运动硬化
concrete
irreversible thermodynamics
isotropic hardening
kinematic hardening
