建立了TC4钛合金薄板激光焊接模型，采用有限元方法分析了板宽对焊接残余应力及失稳变形的影响。结果表明：最高纵向残余拉应力出现在焊缝中心两侧的热影响区；随着板度增大，平均残余压应力和临界失稳力降低；沿着焊接方向的钛合金薄板失稳变形程度随板宽的增加而减小，而垂直于焊接方向的失稳变形程度随板宽的增加而增大；当板宽为120 mm时，其失稳变形程度呈马鞍形分布，当板宽为320 mm时，马鞍形变形分布特征消失；钛合金薄板失稳变形的z向位移试验值与模拟结果的相对误差为8%，证明模拟结果较准确。

Model for laser welding of TC4 titanium alloy thin sheet was established. The effects of sheet width on welding residual stress and instability deformation of titanium alloy sheet were analyzed by finite element method. The results show that the maximum longitudinal residual tensile stress appeared in the heat affected zone on both sides of the weld center. With the increase of sheet width, the average residual compressive stress and critical instability force decreased. The instability deformation thin of the titanium alloy degree sheet along the welding direction decreased with the increase of sheet width, while that perpendicular to the welding direction increased with sheet width increasing. When the sheet width was 120 mm, The distribution of instability deformation degree of the sheet was saddle-shaped. When the sheet width was 320 mm, the saddle-shaped deformation distribution characteristic disappeared. The relative error between the experimental value of z-direction displacement and the simulation of the instability deformation of titanium alloy thin sheet was 8%, indicating that the simulation was relatively accurate.