考虑裂尖不同塑性状态的工业纯钛断裂参量与疲劳裂纹扩展速率模型  

FRACTURE PARAMETER AND FATIGUE CRACK GROWTH RATE MODEL FOR COMMERCIAL PURE TITANIUM UNDER DIFFERENT CRACK TIP PLASTIC STATES

作　　者：李建 徐英东 沈程骏 戴承霖 徐涵 朱建国 周昌玉[4] LI Jian;XU YingDong;SHEN ChengJun;DAI ChengLin;XU Han;ZHU JianGuo;ZHOU ChangYu(Institute of Structural Health Monitoring,Faculty of Civil Engineering and Mechanics,Jiangsu University,Zhenjiang 212013,China;National Center for International Research on Structural Health Management of Critical Components,Jiangsu University,Zhenjiang 212013,China;School of Energy and Power Engineering,Jiangsu University,Zhenjiang 212013,China;School of Mechanical and Power Engineering,Nanjing Tech University,Nanjing 211816,China)

机构地区：[1]江苏大学土木工程与力学学院结构健康管理研究院,镇江212013 [2]江苏大学高端装备关键结构健康管理国际联合研究中心,镇江212013 [3]江苏大学能源与动力工程学院,镇江212013 [4]南京工业大学机械与动力工程学院,南京211816

出　　处：《机械强度》2024年第6期1481-1486,共6页Journal of Mechanical Strength

基　　金：中国博士后基金面上项目(2020M681496);国家自然科学基金项目(52105149)资助。

摘　　要：考虑到裂尖不同程度的塑性变形,选择合适的断裂参量并准确预测疲劳裂纹扩展速率是一项非常重要的任务。采用4种不同疲劳加载条件,通过理论计算与实验分析探究了裂纹尖端断裂参量与疲劳裂纹扩展速率之间的关联,最后通过公式与参数拟合对疲劳裂纹扩展速率预测提供合适的模型。结果表明,随着载荷比和载荷幅的提高,ΔK表征疲劳裂纹扩展逐渐失去了其合理性和有效性。裂纹扩展前期,高载荷比裂纹扩展阻力更大。在裂纹扩展后期,高、低载荷比裂纹扩展阻力差距在缩小。在所有讨论的断裂参量中,ΔJ′_(ac)是适合工业纯钛疲劳裂纹扩展的断裂参量,在此基础上提出了相应的疲劳裂纹扩展速率预测模型。It's an important task that choosing appropriate fracture parameters and predicting the fatigue crack growth rate accurately considering the different degrees of plastic deformation at the crack tip.The relation between crack tip fracture parameters and a fatigue crack growth rate was investigated by theoretical calculation and experimental analysis under four different fatigue loading conditions.Finally,a suitable model for predicting a fatigue crack growth rate was provided by formulas and the parameter fitting.The results indicate that ΔK representing a fatigue crack growth rate loses its rationality and effectiveness gradually with increases of the load ratio and the load amplitude.At the early stage of the crack propagation,the crack propagation resistance of high load ratio is higher than low load ratio.At the later stage of the crack propagation,the gap between high and low load ratios and the crack growth resistance decreases. ΔJ'_(ac) is the suitable fracture parameter for the fatigue crack propagation of the industrial pure titanium among all of the fracture parameters discussed.On this basis,the corresponding prediction model of the fatigue crack growth rate was proposed.

关 键 词：疲劳裂纹扩展 断裂参量 预测模型 载荷比 载荷幅 

分 类 号：O346.1[理学—固体力学]