基于近场动力学的钛合金TC4材料疲劳裂纹扩展建模  

MODELING OF FATIGUE CRACK PROPAGATION IN TITANIUM ALLOY TC4 MATERIAL BASED ON THE PERIDYNAMIC THEORY

作　　者：刘宗晖 陈荣[2] 米栋 曹凡 韩俊昭[2] LIU ZongHui;CHEN Rong;MI Dong;CAO Fan;HAN JunZhao(Hunan Aviation Powerplant Research Institute,Aero Engine Corporation of China,Zhuzhou 412002,China;School of Mechanical Engineering,Zhejiang Sci-Tech University,Hangzhou 310018,China)

机构地区：[1]中国航发湖南动力机械研究所,株洲412002 [2]浙江理工大学机械工程学院,杭州310018

出　　处：《机械强度》2024年第6期1465-1473,共9页Journal of Mechanical Strength

基　　金：国家科技重大专项项目(J2019-Ⅷ-0001-0162)资助。

摘　　要：为了更准确地预测钛合金TC4材料在循环载荷下的疲劳裂纹扩展行为,提出了一种基于近场动力学理论的新型预测模型,首先在近场有限半径内构建了物质点损伤模型,用以模拟裂纹的产生及其扩展过程;通过建立“键”的塑性变形损伤模型,深入分析了疲劳裂纹的萌生和扩展机制,为提升模型的预测效率和稳定性,引入了物质点临界损伤因子这一关键参数;并采用了改进的自适应动态松弛方法,该方法在每个加载循环中都能获得静力解,并通过对不同载荷条件下的裂纹扩展结果进行收敛性分析,进一步验证了模型的可靠性。实验结果表明,所提出的基于近场动力学理论的疲劳裂纹扩展预测模型,可以准确地预测裂纹的萌生位置和扩展速率;模型预测的疲劳寿命与实验数据呈现出良好的一致性,该模型在钛合金材料疲劳裂纹扩展预测方面具有有效性和实用性。In order to more accurately predict the fatigue crack propagation behavior of titanium alloy TC4 under cyclic load,a new prediction model based on peridynamics theory was proposed.Within a finite near-field radius,a material point damage model was constructed to simulate the initiation and propagation of cracks.By establishing the plastic deformation damage model of the"bond",the mechanism of fatigue crack initiation and propagation was deeply analyzed in this study.In order to improve the prediction efficiency and stability of the model,the critical damage factor of material point was introduced,and an improved adaptive dynamic relaxation method is adopted.The static solution can be obtained in each loading cycle,and the reliability of the model was further verified by the convergence analysis of the crack propagation results under different loading conditions.The experimental results show that the fatigue crack growth prediction model based on peridynamics theory can accurately predict the crack initiation location and crack growth rate without relying on additional crack growth criteria.In addition,the fatigue life predicted by the model is in good agreement with the experimental data,which proves the validity and practicability of the model in predicting fatigue crack growth of titanium alloy materials.

关 键 词：近场动力学模型 钛合金TC4 疲劳裂纹 裂纹扩展 疲劳寿命 

分 类 号：TH142[一般工业技术—材料科学与工程]