Abstract A new fatigue crack growth rate model is proposed considering overload effect, which could quantitatively describe the crack growth rate considering overload from variable-amplitude load. Residual stress intensity factor K q caused by overload was put forward by defining stress ratio R c and obtained by XFEM. Three typical overload situations are studied and reappearance of the threshold stage was elaborated by compact tension tests. The effective scope of the overload is the width of the plastic zone, within the region the stress ratio rises quickly and then become stable. Threshold stage reappeared only when overloads by the higher preload effect were conserved.

中文翻译：

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裂纹尖端过载对7005铝合金裂纹扩展速率影响的定量分析

摘要 提出一种新的考虑过载效应的疲劳裂纹扩展速率模型，该模型可以定量描述考虑变幅载荷过载的裂纹扩展速率。通过定义应力比R c 提出过载引起的残余应力强度因子K q ，并通过XFEM 求得。研究了三种典型的过载情况，并通过紧凑的拉伸试验阐述了阈值阶段的再现。过载的有效范围是塑性区的宽度，在该区域内应力比迅速上升然后趋于稳定。仅当较高预载效应引起的过载得以保存时，阈值阶段才会重新出现。