The von mises plastically deformed enclave as heat source for running cracks
The von mises plastically deformed enclave as heat source for running cracks
复制标题
冯·米塞斯塑性变形飞地作为裂纹扩展的热源
DOI：
10.1016/0020-7683(92)90106-4
复制
发表时间：
1992
影响因子：
3.6
通讯作者：
N. Andrianopoulos
中科院分区：
文献类型：
--
作者：
P. Theocaris;S. K. Kourkollis;N. Andrianopoulos
所有现有的模型相互关联的裂纹扩展特性与热交换在裂纹尖端周围的区域模拟的热产生区域的简单的几何形状，如圆形或正方形。它们还假定整个区域或热源的产热率恒定。此外，在本研究中引入的模型是基于两个改进的和更现实的假设，关于热源的形状和尺寸和热源内的热产生密度的空间分布。这些假设，再加上Roscnthal的移动点源解决方案，产生一个合理的和改进的模型，快速和相当简单的数值方法，其结果与现有的实验证据一致。将该方法应用于两种不同的材料，一种是聚合物（聚碳酸酯），另一种是金属（铝合金），它们的结果似乎与实际相符，并与各自的实验相一致。此外，该方法被应用于相对较高的裂纹扩展速度揭示了两个对称的离轴温度极值存在于裂纹扩展轴的一侧。这种现象可能与裂纹分支现象直接相关。其中在相同的速度下系统地观察到类似的能量最大值和分支方向。
All existing models interrelating crack propagation characteristic properties with heat exchange in zones around the crack tips simulate the heat production area by simple geometrical forms, like circles or squares. They assume also constant heat production rates over the whole area or the source. Contrariwise, the model introduced in the present study is based on two improved and more realistic assumptions concerning the shape and dimensions of the heat source and the spatial distribution of heat production density inside the heat source. These assumptions, together with Roscnthal's moving-point-source solution, yield a reasonable and improved model for a fast and rather simple numerical approach, whose results are in agreement with existing experimental evidence. The method was applied to two different materials, one polymer (polycarbonate) and the other metal (aluminum alloy) and their results appear to he compatible with reality and concordant with respective experiments In addition, the method was applied to relatively high crack propagation velocities revealing the existence of two symmetric off-axis temperat lire extrema in cither side of the crack propagation axis. This behavior may be directly relaled lo the phenomenon of crack branching. where similar maxima of energies and directions of branching are systematically observed at the same velocities.