金属桁架结构成形工艺分析

针对电弧增材制造过程中桁架结构难以制造的问题，提出一种基于冷金属过渡（CMT）点焊工艺的逐点添加空间桁架结构增材制造技术.通过工艺成形试验获得最优的工艺参数，并对桁架结构焊接过程进行受力分析，建立桁架结构制造过程受力数学模型，有效地解决了成型过程中立柱的下榻、熔滴在立柱上的下淌以及焊枪轮廓与构件的碰撞问题.通过受力分析数学模型得出，焊枪以垂直于基板的方向对桁架结构进行堆积时，桁架立柱出现下塌现象的临界角为50°.将数学模型与桁架结构成型路径策略相结合，可以对复杂立体特征桁架构件进行增材制造.最后通过改变单个立柱弯曲角度的桁架结构增材试验，得到满足成型精度要求的桁架结构件，验证了数学模型的正确性及桁架焊成形方法的可行性.

Research on forming technology of metal truss structure

Aiming at the problem that it is difficult to manufacture truss structures, this paper proposes a point-by-point additive manufacturing technology for space truss structures based on cold metal transition (CMT) spot welding. First, the optimal process parameters are obtained through process forming tests, and then the force analysis during the welding process of the truss structure is performed. Based on the force analysis in this paper, a mathematical model of the force analysis in the truss welding manufacturing process is proposed on this basis, which effectively solves the collapse of the column, the drip of molten droplets on the column, and the collision of the torch contour with the component during the truss forming process. Finally, a truss forming test was performed to change the bending angle of a single column to verify the correctness of the mathematical model and the feasibility of the truss welding method.