基于能量等效的混凝土结构疲劳断裂仿真分析方法

Energy-based numerical simulation on fatigue damage-fracture process of concrete structures

为了实现混凝土结构损伤-断裂的全过程分析,推导疲劳裂纹扩展与疲劳损伤区演化之间的耗散能等效关系,将离散的裂纹转化为等效损伤区,采用连续介质力学的有限单元法,对于损伤与完好区域分别采用不同的弹性模量来模拟,并将TrishaSain等提出的2D分析方法推广到3D复杂应力状态下,采用通用的有限元分析软件,实现混凝土疲劳裂纹扩展及其刚度、强度衰减过程的仿真。通过对文献疲劳试验的模拟分析,结果表明本方法能准确模拟开裂混凝土构件疲劳失效过程。

For the sake of implementing damage and fracture-based full process analysis of concrete structures,a energy equivalent relationship between damage evolvement and crack spreading under fatigue load has been deduced.At first,the discrete crack has been transferred to successive equivalent damage zone,which is described by the length and width.The finite limited element method is adapted to simulate the concrete structures with discriminating the damaged and intact zone by varied Modulus of elastic.Then,a general finite limited element software based computational flowchart for simulation the reduction of strength and stiffness of concrete structures is proposed in present study.The fatigue tests conducted by Wu et.al.are numerical investigated in the end section of this article,and the results shown herein can meet the common rules which had been observed in other experiments.