厚壁筒内表面平行双轴向裂纹间影响规律研究  

Factors influence on the interference of parallel biaxial cracks in inner surface of thick-walled pipe

作　　者：秦媛媛 秦晓峰 陈占春 QIN Yuan-yuan;QIN Xiao-feng;CHEN Zhan-chun(College of Mechanical and Vehicle Engineering,Taiyuan University of Technology,Taiyuan 030024,China;Shanxi Province Virtual Simulation Experimental Teaching Center,Taiyuan 030024,China)

机构地区：[1]太原理工大学机械与运载工程学院,山西太原030024 [2]山西省虚拟仿真实验教学中心,山西太原030024

出　　处：《机电工程》2022年第2期276-280,共5页Journal of Mechanical & Electrical Engineering

基　　金：山西省自然科学基金青年基金资助项目(201901D211012);山西省回国留学人员科研教研资助项目(HGKY2019020;2021048)。

摘　　要：厚壁筒类结构在服役过程中,内壁产生的裂纹对强度和安全使用具有重要影响,针对这一问题,对厚壁筒内表面平行双轴向裂纹间相互作用影响规律进行了研究。首先,在基于理论公式分析轴向单裂纹应力强度因子影响因素的基础上,定义了表征双轴向裂纹间相互影响和作用的相互作用影响因子λ;然后,采用有限元方法,对不同裂纹间夹角、不同裂纹深度比以及不同厚壁筒外径情况下,双轴向裂纹尖端应力强度因子进行了计算;最后,通过计算结果,分析了不同因素改变时,对厚壁筒内表面平行双轴向裂纹之间相互作用及其裂纹尖端应力强度因子的影响。研究结果表明:双轴向裂纹之间相互影响的闭合效应和张开效应受裂纹间夹角的影响,且存在一个临界值;当双轴向裂纹夹角大于临界值时,随着夹角值、裂纹长度与壁厚比和直径与壁厚比的增加,张开效应增强;反之则相反。Aiming at the problem that the cracks on the inner wall of the thick-walled tube structure have an important influence on the strength and safe use during the service process,the mutual influence law of the parallel biaxial cracks on the inner surface of the thick-walled tube was studied.An interaction impact factor λ was defined based on analysis of theoretical formula of stress intensity factor of thick wall pipe single axial crack.According to finite element method,stress intensity factors of double axial surface cracks in thick-walled cylinders were calculated in different situation of angles,ratio of crack length to wall thickness and ratio of our diameter to wall thickness.The variations of different influencing factors on the interaction between parallel biaxial cracks on the inner surface of thick-walled cylinder and the stress intensity factor at the crack tip were analyzed through the calculation results.The results indicate that there is a critical angle determining the closure and opening effect between the biaxial cracks.When the angles between biaxial cracks are larger than the critical value,the opening effect can be strengthened with the increase of angles value,ratio of crack length to wall thickness and ratio of our diameter to wall thickness,and vice versa.

关 键 词：厚壁筒 应力强度因子 双轴向裂纹 相互作用影响因子 

分 类 号：TH49[机械工程—机械制造及自动化]