【摘要】 对 19Mn6合金钢疲劳试样进行了系列低周疲劳试验 ,采用光学金相方法观察了试样表面微裂纹的萌生和扩展规律 ,基于损伤局部性概念对疲劳局部损伤规律提出了细观疲劳局部损伤参数DW 。DW 随施加的疲劳循环而呈指数增加 ,一直达到临界值 1。损伤非线性因子m值较宏观测量方法所得结果明显降低更多还原

【Abstract】 Low cycle fatigue tests were carried out on a number of fatigue specimens of 19Mn6 steel. Multiple small cracks initiated on the surface and their propagation were observed by optical metallography. A parameter, D W , is proposed for quantitative description of local fatigue damages based on local damage concept. D W increases exponentially with the number of recycles until reaching the critical value, 1. The nonlinear damage factor, m , obtained by correlation of the experimental data is smaller than that by macro measurement.更多还原