摘要
1.疲劳裂纹起始扩展门槛值(△K_(th))的概念 人们通常提到的疲劳裂纹扩展门槛值△K_(th)是在裂纹扩展过程中不断下降△K,使裂纹扩展不断减慢,直至停止扩展时所对应的△K值。它由降K程序测定,试验方法见文献。达到△K_(th)时裂纹前缘塑性区很小,在厚度和应力比一定的条件下,△K_(th)是材料常数。然而,在构件承受变幅交变载荷作用时,某级载荷使裂纹尖端产生应力强度因子K_(fmax)。
A new threshold,the fatigue crack initiation growth threshold(ΔKth)i,is proposed in this paper. It is showed by test research that the(ΔKth)i values corresponding to given Kfmax under the same material and stress ratio don't change with crack length, and the functional relationship between (ΔKth)i and Kfmax is nearly linear.
出处
《航空学报》
EI
CAS
CSCD
北大核心
1989年第12期B659-B661,共3页
Acta Aeronautica et Astronautica Sinica
关键词
裂纹扩展
疲劳
门槛值
飞机结构
fatigue crack initiation growth threshold, fatigue crack growth threshold.
