Simulation of local instabilities during crack propagation in the ductile–brittle transition region
Simulation of local instabilities during crack propagation in the ductile–brittle transition region
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DOI：
10.1016/j.euromechsol.2010.12.013
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发表时间：
2011-05
影响因子：
4.1
通讯作者：
G. Hütter;Uwe Mühlich;M. Kuna
中科院分区：
文献类型：
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作者：
G. Hütter;Uwe Mühlich;M. Kuna
对弹塑性材料中的内聚区模型在小范围屈服条件下的裂纹扩展进行了数值模拟。由此产生的裂纹扩展阻力曲线示出局部不稳定性，即使对于均匀的内聚性质，如果内聚强度足够接近相应的钝化解决方案的最大应力，也会出现所谓的弹出。二次裂纹和卸载区的实际裂纹尖端前面的形成被确定为潜在的机制。研究发现，内聚规律的形状对止裂行为有相当大的影响。此外，对网格分辨率的要求。
The crack propagation for a cohesive zone model within an elastic-plastic material under small-scale yielding conditions is simulated numerically. The resulting crack growth resistance curves show local instabilities, so-called pop-ins even for homogeneous cohesive properties if the cohesive strength lies sufficiently close to the maximum stress of the corresponding blunting solution. The formation of secondary cracks and unloading zones in front of the actual crack tip is identified as the underlying mechanism. It is found that the shape of the cohesive law has a considerable influence on the crack arrest behavior. Furthermore, requirements to the mesh resolution are derived.