Finite Element Study of Near-Tip Field for Growing Cracks

将在波音计算机服务部的Gray XMP/24上获得访问设备和100个CPU小时，并将生成平面应变扩展裂纹的非常详细的有限元解决方案。这些计算将确定裂纹稳定扩展过程中尖端附近应力场和变形场的演化，并估计其与裂纹扩展历史的函数关系。对深度裂纹弯曲几何结构，在从小尺度发展到大尺度的条件下，进行包括屈服在内的裂纹扩展模拟。对于不同合理选择的载荷对裂纹长度的历史，将寻求近尖端场的准确的数值描述。总体目标是将这些结果用于延性裂纹扩展方程，并用实验结果验证它们。

Access equipment and 100 CPU hours on the Gray XMP/24 at Boeing Computer Services will be obtained and very detailed finite element solutions for plane strain growing cracks will be generated. The computations will determine the evolution of the near-tip stress and deformation fields during stable crack growth and estimate its functional dependence on the crack growth history. Crack growth simulations will be performed for a deeply cracked bend geometry under conditions which progress from small scale to large scale, including yielding. Accurate numerical description of the near-tip fields will be sought for different judiciously chosen load versus crack length histories. The overall goal is to utilize these results on ductile crack growth equations and verify them with experimental results.