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用有限元方法对平面应力条件下弹塑性材料的裂纹尖端应力应变场进行了计算。结果表明,在尖端附近存在着一个大小随加载水平的变化而改变的HRR场,在HRR场之外的远程场与试样的几何类型有关。这一结果从滑移线场浸蚀花样观察及显微硬度试验得到证实。此外,试验表明起裂的裂纹张开位移值与滑移线场类型无关,它由HRR场控制,而裂纹的稳态扩展行为则受到远程场的影响。
The stress and strain field at the crack tip of the elastic-plastic material under plane stress are calculated by the finite element method. The results show that there is a HRR field whose size varies with the loading level near the tip. The remote field outside the HRR field is related to the geometry of the specimen. This result is corroborated by slip pattern observation and microhardness test. In addition, the experimental results show that the crack initiation displacement is independent of the type of slip line field. It is controlled by the HRR field and the steady-state propagation of crack is affected by the long-range field.