重点解决了激光冲击强化后试件的疲劳仿真,进一步深入研究了激光冲击强化对疲劳寿命的影响。对两组7050-T7451铝合金试件进行了拉拉疲劳试验,两组试件分为普通试件和激光冲击强化试件。试验结果表明,在101.3 MPa的加载应力水平下,两组平均疲劳寿命分别为26024和108336周次,疲劳寿命提高到原来的416.3%。利用有限元软件对两组试件分别进行疲劳数值模拟。模拟结果显示,两种疲劳寿命分别为25400和102870周次,疲劳寿命提高到原来的405%。试验结果和模拟结果符合得很好。研究表明,激光冲击强化后会在试件表层产生压应力,可以显著提高试件的疲劳寿命。
This paper mainly simulates the fatigue life of specimens treated by laser shock processing(LSP),and studies the effects of LSP on fatigue life.Two groups of 7050-T7451 aluminum alloy specimens pull-pull experiment are performed.One group of specimens is untreated,while another is treated.The results of experiment indicate that under the stress of 101.3 MPa,two groups of average fatigue life are 26024 and 108336 cycles respectively,raised to 416.3%.The results of numerical simulation indicate that two groups of average fatigue life are 25400 and 102870 cycles respectively,raised to 405%.The result of experiment agrees with that of numerical simulation quit well.The study shows that the residual stress is generated by LSP on the surface of specimen,thus the fatigue life increases obviously.