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建立了铝合金在细观尺度下局部区域有多个孔洞(缺陷)的有限元分析模型,采用带有应力三轴度的断裂准则,进行裂纹扩展模拟。结果表明:由于孔洞的存在,初始阶段就开始出现了应力集中,应力较大的点上应变会增加很快,导致应力集中带变得越来越窄;随加载不断的加强,裂纹开始形成,小段裂纹开始在两个孔洞之间形成,然后向孔洞方向慢慢扩展;随载荷不断增加,孔洞之间的小段裂纹已经扩展到与孔洞相接,形成了一条大裂纹。通过对不同温度下的裂纹扩展过程进行模拟,分析后得出,随温度升高,裂纹扩展的速率减小。
A finite element model of aluminum alloy with multiple holes (defects) in the local area at the mesoscopic scale was established. The crack propagation simulation was carried out by using the fracture criterion with stress triaxiality. The results show that due to the existence of holes, stress concentration starts to occur in the initial stage, and the strain at the point of larger stress will increase rapidly, resulting in the narrower the stress concentration zone. With the increasing load, the crack begins to form, Small cracks begin to form between the two holes and then slowly expand toward the holes. With the increasing load, the small cracks between the holes have been extended to connect with the holes, forming a large crack. By simulating the crack growth process at different temperatures, it is concluded that as the temperature increases, the rate of crack propagation decreases.