The geometry of the cladding pass cross section cannot be easily predicted in laser melting deposition. Due to the huge difference between the actual and the predicted cross section, it is difficult to conduct numerical simulations. In this paper, the finite element method (FEM) with thermal–mechanical coupling is performed. A novel cladding pass cross section model, isosceles trapezoid model, is proposed. The comparisons between the isosceles trapezoid model and the traditional model (disk model and rectangle model) are performed in terms of geometrical deviation, heat dissipation, temperature field, and stress field. The results show that the geometrical deviation and heat dissipation between trapezoid model and disk model is small, and that between trapezoid model and rectangle model is large. The trapezoid model has an additional degree of freedom for modeling, i.e., contact angle, which helps to conform complex cross section geometry more flexibility. The results of temperature field and stress field show that the deviation between the isosceles trapezoid model and the traditional models is small on the upper surface of the sample, and rectangle model has worse prediction results than the other two models at the interface between cladding pass and substrate. Finally, the validation experiment is carried out and the stress is measured by laser ultrasound technique. The experimental result matches the FEM result based on isosceles trapezoid model.

在激光熔化沉积中不能轻易地预测包层通过横截面的几何形状。由于实际横截面和预测横截面之间的巨大差异，因此很难进行数值模拟。在本文中，进行了热-机械耦合的有限元方法。提出了一种新颖的熔覆通过截面模型，等腰梯形模型。等腰梯形模型与传统模型（圆盘模型和矩形模型）之间的比较是在几何偏差，散热，温度场和应力场方面进行的。结果表明，梯形模型与圆盘模型之间的几何偏差和散热较小，梯形模型与矩形模型之间的几何偏差和散热较大。梯形模型具有附加的建模自由度，即接触角，有助于使复杂的横截面几何形状更加灵活。温度场和应力场的结果表明，等腰梯形模型与传统模型在试样上表面的偏差小，矩形模型在熔覆道与熔接界面上的预测结果较其他两个模型差。基质。最后，进行了验证实验，并通过激光超声技术测量了应力。实验结果与基于等腰梯形模型的有限元结果相匹配。温度场和应力场的结果表明，等腰梯形模型与传统模型在试样上表面的偏差小，矩形模型在熔覆道与熔接界面上的预测结果较其他两个模型差。基质。最后，进行了验证实验，并通过激光超声技术测量了应力。实验结果与基于等腰梯形模型的有限元结果相匹配。温度场和应力场的结果表明，等腰梯形模型与传统模型在试样上表面的偏差小，矩形模型在熔覆道与熔接界面上的预测结果较其他两个模型差。基质。最后，进行了验证实验，并通过激光超声技术测量了应力。实验结果与基于等腰梯形模型的有限元结果相匹配。