摘要
为研究表面粗糙度（Ｒ）对疲劳强度（△σ）的影响，从Ｆｒｏｓｔ规律△σｍａ＝Ｃ和稳态疲劳门坎关系△Ｋ（ｔｈ）＝２△σ（ａ）（１／２）出发，导出了临界粗糙度的凹槽深度Ｒ０＝Ｃ／△σ０ｍ和长、短裂纹交界点的深度ａ２（ｍ－２）＝（△Ｋ（ｔｈ）／２）（２ｍ）／Ｃ２，当Ｒ小于Ｒ０时，△σ稳定在一极大值△σ０。；当Ｒ在Ｒ０和ａ２之间时，△σ＝（Ｃ／Ｒ）（１／ｍ）；当Ｒ≥ａ２时，△σ＝△Ｋ（ｔｈ）／（２（Ｒ）（１／２））．利用固有裂纹长度ａ０＝（△Ｋ（ｔｈ）／２△σ０）２，可以得到定量关系：ａ０ｍ＝Ｒ０２ａ２（ｍ－２）．计算结果表明其关系与实验结果吻合很好．
In order to study the influence of surface roughness(R)on plain fatigue limit △σbymeans of Frost's law,△σma=C(constant) and the stable fatigue threshold △K(th)=2△σ(a)(1/2),eguations for the critical groove depth R0=C/△σ0mand the bound length between long andshort fatigue cracks.are derived When groove depth R≤R0,△σis sta-bilized at a maximum i.e,△σ0. When R is between R0 and a2,△σ=(C/R)(1/m). When R>a2,△σ=△K(th)/2(R)(1/2). By means of the intrinsic crack length a0=(△K(th)/(2△σ))2,the quantitativerelation is derived. The prediction results show that the relations of the presentpaper agrees with experimental results.
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
1995年第6期90-95,共6页
Journal of Xi'an Jiaotong University
基金
国家自然科学基金
关键词
疲劳强度
疲劳裂纹
表面粗糙度
构件
fatigue strength surface roughness fatigue short crack
