Creep relaxation of stress around a crack tip
Creep relaxation of stress around a crack tip
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DOI：
10.1016/0020-7683(81)90055-x
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发表时间：
1981
影响因子：
3.6
通讯作者：
J. Bassani;F. Mcclintock
中科院分区：
文献类型：
--
作者：
J. Bassani;F. Mcclintock
平面应变数值解已获得幂律蠕变松弛裂纹尖端应力随后的初始弹性响应。显式时间积分与初始应变，有限元计算相结合。对于成本有效的自动时间步长控制，Irons-Treharne-Cormeau稳定时间步长估计用于重新稳定5-50倍大的步长之间的计算。这种有限元格式很容易适用于现实的（和复杂的）蠕变流动关系。给出了在恒定载荷和蠕变指数分别为3和10的情况下，平面应变浅I型拉伸边缘裂纹的数值结果。在小尺度蠕变条件下计算的奇异HRR裂纹尖端场的短时振幅确定的应力是在1.5%的预测，使用弹性应力强度因子KI与Riedel-Rice近似。这是一个较长的时间过渡到一个稳态值，这是给定的路径无关的integralC。随时间变化的裂纹张开位移和速度和蠕变应变超过弹性应变的区域的增长。
Plane-strain numerical solutions have been obtained for the power-law creep relaxation of crack tip stresses subsequent to an initial elastic response. Explicit time integration is coupled with an initial-strain, finite element calculation. For cost effective, automatic time step control, the Irons-Treharne-Cormeau stable time step estimate is used to restabilize the calculation between steps 5–50 times larger. This finite element scheme is readily adaptable to realistic (and complicated) creep flow relations. Numerical results are presented for the plane-strain shallow Mode I tensile edge crack under constant applied load and creep exponents of 3 and 10. The calculated short-time amplitude of the singular HRR crack tip field under small-scale creeping conditions determines stresses that are within 1.5% of those predicted, using the elastic stress intensity factorKIwith the Riedel-Rice approximation. This precedes a longer time transition to a steady-state value that is given in terms of the path-independent integralC∗. Time-dependent crack opening displacements and velocities and the growth of regions where creep strains exceed the elastic strains are also presented.