裂尖塑性区方向应变能裂纹扩展准则及数值模拟

Research on A Criterion and Numerical Simulation for Crack Propagation Based on the Radial Strain Energy at Plastic Core Region

在应用断裂力学和塑性力学对裂纹顶端的分析基础上,提出了裂纹顶端塑性区内方向应变能的概念,并建立了基于此概念上的裂纹扩展准则,模拟了复合型裂纹的扩展行为。在计算过程中,通过修改裂纹顶端与所在单元的节点间的连接关系,实现裂纹扩展的动态跟踪。该方法具有修改范围小,编程方便,可操作性强等特点。文中以单边尖锐缺口试样为算例进行了数值模拟,计算结果表明本文的方法是合理有效的。

A new concept of strain energy along radius from crack tip within plastic zone is presented based on the analysis of deformations behavior of crack tip by the theory of fracture mechanics and plastic mechanics ,and a new criterion of crack propagation is proposed. The trajectories of maxed mode crack propagation are simulated through numerical manifold method. The crack propagation is traced dynamically by modifying the neighboring connection between crack-top and nodes within element in the calculating process. This method has the advantages such as less modifying area, easily programming, more realizable and so on. Then the single sharp nicked specimen is used to verified the numerical result.