钽薄板小间隙TIG氦弧对接焊应力应变场的数值分析

Numerical analysis for stress and strain fields of TIG helium-arc small-gap butt welding of tantalum sheet

针对钽薄板小间隙TIG氦弧焊接的特点,基于有限元分析软件ANSYS,在计算温度场的基础上,采用温度场与应力场间接耦合的方法,对钽薄板小间隙TIG焊接过程中应力应变场进行三维数值动态模拟,分析了间隙存在时工件在热应力作用下应变场的分布情况。计算结果表明在输入有效热量较少时,工件受热应力的作用不明显,应变场变化不大;随着输入有效热量的增加,热应力作用逐渐加强,工件的应变场变化明显,应变速度加快;当工件的温度场达到准稳态时,热应力影响再次减弱,应变速度趋于平缓。工件的最大应变值发生在电弧有效作用范围之内,应变值沿焊接方向随热应力作用的减弱而减小。

According to the characters of TIG helium-arc small-gap butt welding of tantalum sheet,based on ANSYS,after the calculation of temperature field,three-dimensional numerical simulation for stress and strain fields of TIG helium-arc small-gap butt welding of tantalum sheet was carried out.The stress and strain fields when small-gap existed was analyzed.We can get the conclusion from the results as follows：The effect of thermal stress was little and the speed of strain was slow when inputing less heat energy,with the increase of heat energy,the effect of thermal stress was obvious and the change of strain fields became fast.When the temperature fields of workpiece reached steady sub-state ,the effect of thermal stress weakened again and the change of strain fields became gentle. The maximum of tress and strain fields appeared in the effective scope of arc and strain became small in direction of welding with the decrease of effect of thermal stress.