确定焊接反变形的数值模拟及规律分析

焊接接头附近局部的加热及冷却使被焊结构产生残余应力及角变形.目前在船厂精度控制中,通常采用构件焊接后对某些部位进行火工校正的方法来控制残余角变形.文章提供了另外一种有效控制结构残余角变形的方法:对结构焊前施加弹性的反向变形.利用热弹塑性有限元法来模拟结构的焊接过程,并对不同板厚、不同热源的结构分别进行数值模拟,最终确定焊接结构的弹性反变形规律:焊接前施加弹性反变形的结构在焊接后角变形趋于零.

Analysis of the rule of weld reversed angular distortion by FEM

Usually,heating after the structure welded is used as an impediment in accuracy control of the angular distortion in shipyards. In this paper,another effective impediment is offered to control the angular distortion: impose elastic reversed angular distortion before welding. The welding process of no reversed angular distortion is simulated by using thermal elasto-plastic finite element techniques to evaluate the residual angular distortion of the T-joint in fillet weld,then the welding process imposing reserved angular distortion. Sequentially,a series of welding processes was calculated,which is different in both the thickness of the plate and heat flux,and the rule of weld reversed angular distortion was analyzed: all the structures reversed angular distortion is almost horizontal after weld.