喷丸强化对民用飞机腐蚀损伤构件残余应力及疲劳寿命的影响

Effects of Shot Peening on Residual Stress and Fatigue Life of Corrosion Damaged Structural Part of Civil Aircraft

以修理过程中去除腐蚀产物后的民用飞机腐蚀损伤构件为研究对象,针对7075铝合金损伤试样,采用玻璃弹丸为介质,研究喷丸强化对损伤构件表面残余应力及疲劳寿命的影响。首先通过试验确定获得所需喷丸强度及覆盖率的工艺参数,进而测量不同参数喷丸强化后的构件表面残余应力,并分析残余应力沿构件表面方向的分布规律。通过对构件损伤表面进行喷丸以及连同相邻侧面进行喷丸的不同范围的试验研究,得到构件的不同强化效果。疲劳试验结果表明:当只对损伤表面进行喷丸强化时,疲劳寿命的改善相对有限,而将喷丸区域扩大至与损伤表面相邻的构件侧表面时,疲劳寿命将有大幅度提高。

Influence of shot peening on surface residual stresses and fatigue life of the components was studied using damaged 7075 aluminum alloy specimen after removing the corrosion products during the repairing process of the corroded components of civil aircraft as studying object and glass beads as medium.Firstly,the process parameters were determined by experiment to get the desired shot peening intensity and surface coverage,and then the surface residual stress of the peened specimen by different process parameters was measured and the residual stress distribution along the surface of peened specimen was discussed.The different strengthening effects were obtained through investigating the damaged surface alone or together with two neighboring side surfaces.Results showed that the increase of the fatigue life was unconspicuous if only the damaged surface was shot peened while the increase of the fatigue life was significant if the two neighboring side surfaces were also shot peened with the damaged surface together.