超声复合焊接系统声场模拟及焊接电弧压力分析

Acoustic field modeling of ultrasonic-arc hybrid welding system and analysis of ultrasonic-aided arc pressure

提出了超声复合焊接空间中声场参数的分析方法,根据超声复合焊接特性构建了分析模型,利用COMSOL有限元分析软件模拟分析了声场参数随着发射端半径的变化情况,同时模拟分析了声场参数在不同电弧空间高度的变化规律.采用静态小孔法对不同焊接参数下稳定燃烧的直流U-TIG焊和普通TIG焊的电弧压力分布进行了测量.结果表明,U-TIG焊电弧压力峰值明显高于普通TIG焊,复合电弧能够提高焊接时熔池表面上方的电弧压力水平,但是随着电流增加,U-TIG焊和普通TIG焊电弧压力峰值的差值减小.分析认为大电流时,弧柱中心区域温度很高,电流密度很大,使TIG焊电弧压力峰值明显升高,而U-TIG焊电弧等离子流力受到气体流量的限制,电弧压力峰值增幅减小.

Acoustic field analysis of space wave propagation used for ultrasonic-aided TIG welding was proposed and finite element simulation analysis of sound field variation with acoustic emission radius and that of the acoustics parameters variation with arc length was employed with COMSOL. Besides,a new model was also established for ultrasound-aided TIG welding characteristics. Distribution of arc pressure for stable combustion DC U-TIG arc and that of conventional TIG arc under different welding parameters were measured experimentally by using a hole drilling method. The result reveals that arc peak pressure of DC U-TIG is significantly higher than that of conventional TIG,which illustrates that the effect of hybrid-arc can enhance the arc pressure above the surface of weld pool,but the D-value between them decreases with the welding current increases. Preliminary analysis suggests that when high welding current is employed,the high temperature and large current density in the central area of arc column greatly improve the arc peak pressure of conventional TIG. In contrast,the increase of arc peak pressure is reduced with the increase of weld current because plasma flow force of welding arc is limited by gas-flow rates.