【摘要】 简介了循环Ｊ积分ΔＪ＊ｐａｔｈ体系，以１６ＭｎＲ钢单边椭圆孔边裂纹试件进行了６种循环应力比的恒幅应变疲劳裂纹扩展试验，采用材料应变疲劳循环加载条件下的应力－应变关系，通过弹塑性有限元素法计算ΔＪ＊ｐａｔｈ参量，研究了孔边高应变区裂纹塑性应变疲劳扩展规律。结果表明：ΔＪ＊ｐａｔｈ能够作为缺口高应变区裂纹塑性应变疲劳扩展的控制参量，与裂纹扩展速率ｄａ／ｄＮ之间的指数关系，可通过相同材料的标准试件应力疲劳裂纹扩展由Ｐａｒｉｓ公式与ΔＪ＊ｐａｔｈ＝ΔＫ２／Ｅ转换得到。更多还原

【Abstract】 The concept of cyclic J integral Δ J * path proposed by the authors was briefly illustrated. In order to study the behavior of plastic strain fatigue crack growth (PSFCG) in the high strain zone of the notch , the constant amplitude PSFCG tests with six R ratios were performed on the single edge elliptical notch crack plates(SENCP) fabricated from 16MnR steel, while Δ J * path was calculated employing the material stress strain relation under the PSFCG from the elastic plastic finite element method. According to these experiment results, Δ J * path can be employed as a parameter predicting the PSFCG rate in the notch, and the d a /d N vs. Δ J * path relation for PSFCG is consistent with the Paris equation of the same material obtained by elastic stress fatigue crack growth test carried on the standard specimen, except that the Δ J * path was used in terms of the Δ K through Δ J * path =Δ K 2/E .更多还原