角焊缝角变形产生机制的研究

以T形焊接接头为算例,用有限元数值计算方法研究了六个固有应变分量各自对角焊缝角变形的作用效应,发现导致角变形产生的主要因素是与焊缝平行的平面内垂直于焊缝方向的固有剪切应变分量;将该固有剪切应变分量以均匀和非均匀两种分布形式施加在焊缝区,发现只有非均匀分布的固有剪切应变使焊接接头产生角变形.由此可知:角焊缝角变形产生的主要原因是在焊缝及其附近区域不均匀分布的固有剪切应变分量,而不是板厚方向上非均匀分布的横向固有正应变分量.此结论指出了关于焊接角变形产生机制的传统思维的认识误区,对研究预测角焊缝角变形简化方法具有指导意义.

Researches on the coming into being mechanism for fillet weld's angular distortion

Taking a welded T-joint as computing example,the work effect of each inherent strain component upon fillet weld's angular distortion is studied through FEM numerical method.It is found that the main source of angular distortion is the inherent shear strain component that is vertical to the weld line and exists in the plane paralleling to weld line.Comparison is made to distribute this shear strain component in welding region in even and uneven modes successively and it is found that only uneven shear strain results in angular distortion.All these show that it is the inherent shear strain component existing in the weld region unevenly but not the transverse inherent normal component exiting unevenly in weldment thickness direction that mainly induces angular distortion for fillet weld.This conclusion points out the traditional misunderstanding about the mechanism for welding angular distortion coming into being.It has direct meaning to study the simplified methods for forecasting welding angular distortions.