1. 前言疲劳裂纹扩展速率(da/dN) 不仅是表征材质抗疲劳断裂性能的重要指标,而且是损伤容限设计必不可少的基本参数。本文主要讨论恒幅疲劳裂纹扩展速率在10~(-3)-10~(-5)mm/cycle范围内所受应力比R的影响。目前国内外对这个问题的看法分歧较大,Ritchie在1977年的文章中认为影响较小,而1981年的文章中又改变了这种观点。我们在完成的《航空金属材料疲劳裂纹扩展速率数据汇编》中对七种材料、23种状态各测试了三种不同R的da/dN,得到了一些有意义的结果,为工程设计提供了部分依据;同时证明用有效参数法处理铝合金的R对da/dN的影响是可行的。 1. INTRODUCTION The fatigue crack growth rate (da / dN) is not only an important index for characterizing the fatigue fracture resistance of materials, but also an indispensable basic parameter for damage tolerance design. This paper mainly discusses the influence of the stress ratio R under the range of 10-3 (-10-5) mm / cycle for constant amplitude fatigue crack growth rate. At present, there is a wide divergence of views on this issue both at home and abroad. Ritchie considered it as less influential in the 1977 article, which was changed in the 1981 article. We tested da / dN of three different Rs for seven materials and 23 states for the completed Aerospace Materials Fatigue Crack Propagation Rate Data Collection, yielding some meaningful results, providing some of the engineering design It is proved that the effect of R on da / dN of aluminum alloy by effective parameter method is feasible.