摘要
针对金属管材低应力分离过程中裂纹扩展稳定性差、管材断面平整度低的问题,提出一种双频叠加、变频振动的加载控制方法,探究带有V形切口金属管材的断裂行为。结合金属管材的双频振动特性,提出变频振动控制曲线。在此基础上,利用管材的应力集中效应实现V形切口处疲劳裂纹的萌生与稳定扩展,同时在共振效应下完成管材的快速分离。通过自行研制双频振动系统,对预制V形切口的45钢和6061铝合金管材进行了振动实验研究。实验结果表明,金属管材在给定的变频振动载荷作用下可以实现可控性分离。同时,延长变频作用时间以及叠加相应的高频振动载荷,可以有效提高裂纹扩展的稳定性,使得管材断面更加平整,几何精度更高。
A loading control method of dual frequency superposition and variable-frequency vibration was proposed to investigate the fracture behavior of metal pipes with V-notches in view of the problems of poor stability of crack propagation and low smoothness of pipe section in the process of low stress separation of metal pipes. The control curve of the variable frequency vibration was proposed based on the characteristic dual frequency vibration using metal pipes. On this basis,the initiation and propagation of fatigue crack at V-notch were realized by means of the stress concentration effect of pipe,and the rapid separation of the pipe was completed under the resonance effect.Vibration experiments of 45 steel and 6061 aluminum alloy pipes with pre-fabricated V-notches were carried out by self-developed dual frequency vibration system. The experimental results show that the controllable separation of metal pipes can be achieved under the given variable frequency vibration load. At the same time,the stability of crack propagation can be effectively improved by prolonging the time of frequency conversion or superimposing the corresponding high frequency vibration load,and the section of the pipe is smoother and the geometric accuracy is higher as a result.
作者
化春键
王超凡
陆云健
HUA Chun-jian;WANG Chao-fan;LU Yun-jian(School of Mechanical Engineering,Jiangnan University,Wuxi 214122,China;Jiangsu Key Laboratory of Food Manufacturing Equipment Technology,Jiangnan University,Wuxi 214122,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2019年第5期190-196,共7页
Journal of Plasticity Engineering
基金
国家自然科学基金资助项目(61573168)
中央高校基本科研业务费专项基金资助项目(JUSRP11008)
关键词
双频振动
金属管材
控制曲线
应力集中
共振效应
dual frequency vibration
metal pipe
control curve
stress concentration
resonance effect
