双面激光冲击次序对小孔件强化效果影响研究

摘要

小孔构件是典型的应力集中细节,其易在疲劳载荷下产生裂纹,影响关键结构的使用性能和服役寿命. 为了研究双面冲击次序对小孔件强化效果的影响,对双面激光同时冲击强化(双面对冲)和依次冲击强化的TC4-DT小孔构件进行了疲劳拉伸试验,并利用ABAQUS有限元软件,对两种冲击次序强化后的残余应力分布进行了仿真. 结果表明,双面对冲的试样疲劳增益是双面激光依次冲击强化后的2倍以上;双面对冲后小孔件的应力分布更均匀,其疲劳源明显偏离厚度中点处,而双面激光依次冲击时,两激光冲击表面的残余应力差较大. 仿真结果与试验有较好的一致性.%Small-hole components have typical details of stress concentration so that they are easy to produce fatigue cracks under fatigue load and the usage performance and service life of critical structures are easily affected .In order to study effect of two-side laser shock processing ( LSP) order on strengthening of small-hole specimens, fatigue tensile tests of TC4-DT hole components by two-side LSP simultaneously and two-side LSP successively were carried out .ABAQUS finite element software was adopted to conduct simulation study on residual stress distribution of TC 4-DT hole components after different two-side LSP.The results show that the specimen fatigue gain after two-side simultaneous LSP is above 2 times than that after two-side successive LSP.Residual stress distribution of a hole component after two-side simultaneous LSP is more homogeneous .And the fatigue source deviates from the midpoint of the thickness significantly .The difference of residual stress of two LSP surfaces is large after two-side successive LSP .The simulation results have good agreement with the experiment results .