金属材料裂纹扩展Paris律的模拟方法与应用

摘要

结合TA12、TC4钛合金和Cr2Ni2MoV钢的Paris律实验结果,对基于材料的低周疲劳临界损伤获取材料疲劳裂纹扩展Paris律的有限元模拟方法(称为LFF方法)进行了有效性验证,并开展了拓展应用.实验结果与模拟结果比较表明,LFF方法用于模拟材料Paris律有良好准确度.应用LFF方法获得了Cr2Ni2MoV钢、N18合金在多种高温下的Paris模型参数,研究了疲劳裂纹扩展速率的温度效应.%By using of experimental results of low cycle fatigue and fatigue crack growth rate for titanium alloys TA12, TC4 and Cr2Ni2MoV steel, the validity of LFF method for predicting Paris laws of materials based on low cycle fatigue critical damage was verified in this paper. Then LFF method was applied to investigate the temperature effect on fatigue crack growth properties for Cr2Ni2MoV steel and N18 alloy by using the experimental results of low cycle fatigue at different temperatures. The results show that, LFF method can represent material Paris law with high precision. On application of LFF method, the parameters of Paris law for Cr2Ni2MoV steel and N18 alloy at various temperatures were obtained, and the temperature effects were also discussed in detail.