薄板焊接变形高精度预测方法的研究

采用固有应变方法预测焊接变形时,传统方法是把纵向收缩、横向收缩和角变形这三成分作为接头的固有变形来估算焊接变形。但是,由于薄板的刚度低,在纵向方向上的弯曲变形也较明显,采用传统方法会影响薄板焊接变形的预测精度。为提高精度,文章对传统的方法进行了改进,开发了包括考虑纵向弯曲在内的四成分固有变形数值计算方法来预测薄板焊接变形。数值模拟结果表明:运用该方法预测薄板的焊接变形时,比传统的方法有更高的精度,而且预测结果与热弹塑性有限元的模拟结果十分吻合。

Developing an accurate computational approach to predict welding deformation in thin-plate joint

When the elastic finite element method based on inherent strain theory is used to predict weld-ing deformation, longitudinal shrinkage, transverse shrinkage and angular distortion are usually taken as main initial strain components to estimate welding deformation, whereas the longitudinal bending component is often neglected because its magnitude is very limited in many cases. However, if the method without con-sidering longitudinal bending is employed to predict welding distortion for a thin-plate joint, it is possible that a large error will generate because the stiffness of thin-plate structure is relatively small and its out-of-plane deformation is sensitive to the longitudinal bending. In this study, the traditional method above is improved, and a computational approach with considering four components including the longitudinal bend-ing was developed to predict welding deformation for thin-plate structure. Numerical results show that the prediction accuracy of the newly developed method is higher than the traditional method.