TIG焊墙体成型结构的热应力分析

Thermo-Mechanical Study on TIG Welding Deposited Thin-Walled Structures

以简单的墙体成型为例,提出三维热-机耦合模型,用单元生死模拟金属的堆积成型,分析2种不同堆积路径(Z型焊接和同一方向焊接)下的温度场和残余应力分布.结果表明:在不同堆积路径下,温度场和残余应力的分布不同;同一方向焊接所产生的温度场及残余应力比Z型焊接小,但在墙体结束端底部位置,同一方向的Z向应力zσ较高,容易造成墙体和基板断开;Z型焊接在结束端上呈现波动式的高Z向拉应力,容易造成层状撕裂;在熔焊快速制造中,建议焊前对基板进行预热,并在焊后对整个结构进行热处理,以减小残余应力,提高其使用性能.

Taking the simple wall structure as an example,3D thermo-mechanical couple model was developed using the element birth technique to simulate the rapid prototyping(RP) process.The thermal behavior and residual stress were analyzed during the fabrication of a simple wall structure using TIG welding technology.Two cases are studied: a straight wall fabricated by the zig-zag deposition strategy and a straight wall fabricated by the one-direction deposition strategy.It is found that different strategy has differ...