大型纵向桁材式基座焊接变形仿真与控制

Simulation Analysis and Control of Welding Deformation of Large Steel Foundation

基于热弹塑性法对大型纵桁式基座焊接过程进行了有限元分析,采用双椭球热源计算了焊接温度场与应力场,获得了基座焊接残余应力分布及变形情况,并对比分析了圆筒单元4种焊接顺序和3种基座约束方式对焊接变形的影响。结果表明,在压条和定位焊双重约束条件下,按照“头尾交替斜对称”焊接,基座变形最小;优化焊接顺序和约束方式,可有效减小大型基座的焊接变形。

The simulation of welding process of the large stringer steel foundation was established by thermal elastic plastic FEM.By adopting double ellipsoid heat source method,the temperature field and stress field were calculated,therefore the residual stress and the deformation of the foundation structure were acquired.Bedsides,the influences of sequence of four weldings and the three foundation constraint ways on the welding deformation were analyzed.Results showed that under the double restraints of mound layer and tack welding,the deformation was the slightest,and that by optimizing the welding sequence and fixture arrangement,the welding deformation could be reduced effectively.