基于能量耗散机制的混凝土受压损伤模型  

A COMPRESSIVE DAMAGE MODEL OF CONCRETE BASED ON ENERGY DISSIPATION MECHANISM

作　　者：龙渝川[1,2] 李正良[1,2] 

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]重庆大学山地城镇建设与新技术教育部重点实验室,重庆400045

出　　处：《工程力学》2010年第A02期171-177,共7页Engineering Mechanics

基　　金：国家自然科学基金项目(50909109);教育部高等学校博士学科点科研基金(20090191120031);中央高校基本科研业务费资助项目(CDJRC1020005)

摘　　要：为模拟混凝土滞回行为,在传统损伤力学模型中引入非线性卸载-线性重加载路径,然后采用累积耗散能量定义损伤因子,建立了基于能量耗散机制的各向异性受压损伤模型。应用该模型模拟混凝土受压往复加载试验,并进行损伤指数?的敏感性分析。计算结果显示,模型获得的应力-应变响应与试验结果具有良好的可比性,能够反映损伤导致的刚度退化、残余变形累积以及加卸载过程中的滞回耗能现象。同时,损伤指数?的取值对计算精度影响显著,必须完善其率定方法。数值算例表明,该模型可以应用于模拟受压往复加载作用下的混凝土非线性力学行为。An anisotropic compressive damage model based on energy dissipation mechanism is developed to model the hysteretic behavior of concrete by introducing the nonlinear unloading/linear reloading branches into the conventional continuum damage model.The damage factor representing the stiffness degradation is defined as a function of the dissipating energy accumulated during loading histories.The model is applied to simulating a concrete test under cyclic compression and the influence of damage exponent ？ is also investigated.The results show that the stress-strain response calculated by the model is highly comparable to that obtained by the test.The numerical response reflects the nonlinear behavior of concrete under cyclic compression,e.g.the stiffness degradation,accumulation of residual deformation and hysteretic energy dissipation.Moreover,the value of damage exponent ？ has a remarkable influence on the computational accuracy.The numerical simulation shows that the model is applicable to analyzing the behavior of concrete under cyclic compression.

关 键 词：混凝土损伤力学 各向异性损伤模型 滞回能量耗散 刚度退化 残余变形 

分 类 号：TU313[建筑科学—结构工程]