典型孔结构激光冲击强化残余应力场特征及有限元分析

Stress Field Characteristics and Finite Element Analysis of Typical Pore Structures Caused by Laser Shock Peening

研究了TB6钛合金孔结构激光冲击强化后残余应力场分布特征。采用ABAQUS有限元软件建立激光冲击强化模型,运用恒定显式阻尼求解方法,分析激光冲击强化角度、搭接长度、冲击次数等工艺参数对孔结构残余应力场的影响,并与试验测试结果对比分析。结果显示:激光冲击角度对孔内壁位置残余应力值有重要影响,随着冲击角度的增加,残余应力值增加。搭接率对孔角的应力状态无明显影响,冲击次数增加,残余应力也随之增加,但是会逐渐趋于饱和;有限元数值解析的激光冲击残余应力值及演变趋势与试验测试结果吻合较好。

The distribution characteristics of the residual stress field caused by laser shock peening(LSP)were studied in TB6 pore structure.The finite element model of LSP was established by ABAQUS finite element software.The constant explicit damping method was used to analyze the influence of process parameters such as LSP angle,lap length and shock number on the residual stress field of the pore structure,and compared with the experimental test results.The results show that the LSP angle has an important influence on the residual stress value at the pore inner wall.The residual stress value increases with the increase of the LSP angle.The overlapping rate has no obvious effect on the stress state of the pore angle.As the number of shock increases,the residual stress also increases,but it will gradually become saturated.Finite element results including the residual stress value and evolution trend caused by LSP have a good agreement with the experimental test results.