摘要
针对实际工程中安全性与经济性的需求,基于Hutchinson-Rice-Rosengren(HRR)应力-应变场提出一种Ⅰ型疲劳裂纹扩展速率预测模型。采用HRR应力-应变场描述裂纹尖端区域的应力应变分布状态,在考虑循环载荷及应变能密度理论的前提下,定义一个裂纹尖端损伤区域;同时,为消除裂纹尖端的应力奇异值问题,建立考虑裂纹尖端钝化效应的钝化半径计算方法;结合RICE的塑性叠加法与塑性应变能失效准则,发展一种Ⅰ型疲劳裂纹扩展速率模型。利用所提LIUX(HRR)预测模型对9种金属材料裂纹扩展速率进行计算,与Pandey(HRR)与CHEN-CAI Rice-Kujawski-Ellyin(RKE)两种裂纹扩展预测模型计算结果进行对比分析。同时,基于R2拟合效果及疲劳裂纹扩展三阶段的不同需求,给出三种预测模型的预测结果,并从安全性、精确性及经济性三方面给出相应的评分。最终结果表明,LIUX(HRR)预测模型适用范围更广,拟合效果更佳,能够更好地满足实际工程中的经济性与安全性的需求。
Aiming at the safety and economic requirements in practical engineering,a type I fatigue crack propagation rate prediction model was proposed based on the Hutchinson-Rice-Rosengren(HRR)stress-strain field.The stress-strain distribution state of the crack tip region was described by the HRR stress-strain field,and a crack tip damage area was defined under the premise of considering the cyclic load and strain energy density theory.At the same time,in order to eliminate the problem of stress singularity value of the crack tip,a passivation radius calculation method considering the passivation effect of crack tip was established.Combining RICE′s plastic superposition method with plastic strain energy failure criterion,a type I fatigue crack propagation rate model was developed.The crack propagation rates of nine metallic materials were calculated using the proposed LIUX(HRR)prediction model,and the calculation results of the two crack propagation prediction models of Pandey(HRR)and CHEN-CAI Rice-Kujawski-Ellyin(RKE)were compared.At the same time,based on the different requirements of R2 fitting effect and fatigue crack propagation in the three stages,the scoring results of three prediction models were given,and corresponding scores were given from three aspects,safety,accuracy and economy.The final results show that the LIUX(HRR)prediction model in this paper has a wider scope of application,better fitting effect,and can better meet the needs of economy and safety in practical engineering.
作者
刘俭辉
徐建平
LIU JianHui;XU JianPing(School of Mechanical and Electronical Engineering,Lanzhou University of Technology,Lanzhou 730050,China)
出处
《机械强度》
CAS
CSCD
北大核心
2024年第5期1207-1215,共9页
Journal of Mechanical Strength
基金
国家自然科学基金项目(51605212)
甘肃省科技计划项目(20JR10RA161)资助。
