大型底板结构焊接顺序控制变形数值分析

Numerical analysis on optimizing welding sequence of large-sized bottom structure for controlling welding distortion

关键词:  数值模拟  焊接变形  焊接顺序  中性轴

Key words:  numerical simulation  welding deformation  welding sequence  neutral axis

摘要:

利用非线性有限元方法对某大型结构底板焊接顺序进行数值模拟计算,建立了疏密过渡的有限元模型.使用随温度变化的材料热-力参量,采用高效率的移动串状双椭球热源模型,定性地对比了不同焊接顺序及不同约束情况下底板挠曲变形量数值大小.结果表明,先焊底板比先焊筋板方法挠曲变形小;底板两条纵、长焊缝分别焊接比同时焊接方法挠曲变形小;使用刚性平台约束焊接比自由焊接挠曲变形小;筋板两侧横、短焊缝同时焊接不会产生扭曲变形;焊接结构的挠曲变形与结构的中性轴密切相关。

Abstract:

Numerical simulation calculation on welding sequence of bottom plate of large-sized structure is conducted by using non-line finite element model,and the sparse and close finite model is used.The thermo-mechanics parameters of changing with temperature and the high efficient string heat source model of double elliptical are utilized to qualitatively calculate the deflection distortion of different welding sequence and different constraints.The results show that the deflection distortion is smaller for the first welded bottom plates than the first welded stiffened plates,is smaller for the successive welding than the simultaneous welding of bottom plates,and is smaller for using rigid plate constraint welding than non constraint welding.The distortion of the stiffened plate for the successive welding will occur,but the simultaneous welding won't do.The deflection distortion of welded structure relates to the neutral axis of its structure.