穿孔型等离子弧焊接热-力耦合模型优化

发布时间：2018-12-21 15:48

【摘要】：K-PAW的焊接过程是等离子电弧对被焊工件热与力的耦合作用.文中基于FLUENT软件,依据流体动力学理论,对穿孔型等离子弧焊接过程熔池、流场和小孔进行了热-力耦合模型分析,提出了随穿孔深度增加,能量和电弧压力二次变化的计算优化模型,使维持小孔壁面稳定的力同时作用在小孔内部和物理边界上,初步实现了穿孔型等离子弧焊接从开始到穿透工件及穿孔后焊接过程的数值模拟.计算结果表明,焊接时间为0.25 s时,熔池已开始熔化并出现下凹变形,穿孔型等离子弧焊接穿孔时间为2.15 s,焊接3.00 s后小孔和熔池达到稳定状态,与试验测得的穿孔时间吻合良好,在穿孔动态过程中穿孔形态吻合良好,熔合线走势基本相同.另外,在平行于焊缝的截面上观察,熔池内部易出现逆时针环流.
[Abstract]:The welding process of K-PAW is the coupling effect of plasma arc to the heat and force of the welded workpiece. Based on FLUENT software and hydrodynamic theory, the thermal-mechanical coupling model of molten pool, flow field and hole in the process of plasma arc welding with perforation is analyzed, and it is proposed that the model increases with the depth of perforation. The calculation and optimization model of the secondary variation of energy and arc pressure makes the forces that maintain the stability of the wall of the small hole act simultaneously on the inner and physical boundaries of the orifice. The numerical simulation of perforated plasma arc welding from beginning to penetrating workpiece and after perforation is carried out. The calculated results show that when the welding time is 0.25 s, the weld pool has already begun to melt and deformed, the perforated plasma arc welding perforation time is 2.15 s, and the hole and pool are stable after 3.00 s welding. The perforation time is in good agreement with the experimental results, and the pattern of the perforation is good during the dynamic process of the perforation, and the trend of the fusion line is basically the same. In addition, counterclockwise circulation is easy to occur in the weld pool on the cross section parallel to the weld seam.
【作者单位】：江苏科技大学江苏省先进焊接技术重点实验室;北京工业大学机电学院汽车结构部件先进制造技术教育部工程研究中心;
【基金】：国家自然科学基金项目资助(51205176,51675249) 第60批中国博士后基金项目资助
【分类号】：TG456.2

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