针对TIG堆焊所引起的薄板复杂屈曲变形问题，采用基于热弹塑性理论的有限元法建立薄板焊接变形预测模型，提出了数字图像相关法对预测屈曲模型进行试验验证并设计了薄板焊接变形检测试验装置. 结果表明，基于数字图像相关技术的非接触变形检测方法能够全场动态获取堆焊屈曲变形数据，全面验证了焊接变形有限元预测模型，基于高斯热源模型、非线性瞬态热传导边界条件、材料高温性能参数等的热-力耦合热弹塑性预测模型具有较高的精度.薄板焊接变形冷却后呈马鞍形，结合动态温度场与应力场，对揭示焊接马鞍形屈曲变形机理具有重要的意义.
In view of the complex deformation of thin plate caused by TIG bead welding, a thermal-elasto-plastic finite element method was used to establish the prediction model of welding deformation. A non-contact detection method based on digital image correlation technology was proposed to verify the prediction model and a thin plate welding deformation test device was designed. The research shows that the non-contact deformation detection method based on digital image correlation technology can dynamically obtain welding deformation data in the whole field, and can fully verify the welding deformation finite element prediction model. The welding deformation prediction thermo-mechanical coupling model has high accuracy based on Gaussian heat source model, nonlinear transient heat conduction boundary conditions, and material high-temperature performance parameters. The welding deformation of thin plates is saddle-shaped after cooling. Combining the dynamic temperature field and stress field, it is great significance in revealing the mechanism of welding saddle-shaped buckling deformation.
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