基于损伤力学的混凝土疲劳损伤模型

为了研究混凝土在疲劳荷载作用下力学性能不断劣化过程,从连续介质损伤力学的基本理论出发,根据混凝土的材料性能选定合理的耗散势函数,用残余应变来定义混凝土的损伤量,得到关于残余应变的损伤变量表达式;分析混凝土疲劳损伤的发展规律,选用合适的混凝土微塑性应变方程,推导混凝土在疲劳荷载下的损伤发展率,得到混凝土损伤变量与疲劳次数的关系,从而建立混凝土疲劳损伤模型;利用疲劳实验数据验证模型形式的正确性,并确定模型的参数;由此建立耦合损伤变量的混凝土本构关系模型,可用于疲劳荷载作用下混凝土的有限元分析.

Fatigue model of concrete based on continuum damage mechanics

To study the process of concrete mechanical performance degradation under fatigue load,according to continuum damage mechanics the damage is defined in terms of residual strain and the damage equation is deduced based on concrete fatigue performance and reasonable dissipation function.The cumulative damage law of concrete fatigue is investigated and the damage evolution equation is created according to selected appropriate micro plastic deformation expression;the relationship of damage and cyclic number of fatigue is obtained.The fatigue test data validate the modal's general format and the modal parameters are determined.The concrete constitutive properties coupling damage can be used for finite element analysis of concrete under fatigue load.