固有变形计算方法及其在船舶焊接结构变形中的应用

采用基于固有应变法的弹性有限元分析预测大型复杂结构的焊接变形的前提是必须已知焊缝附近的固有变形。结构的焊接残余应力与焊接变形取决于其接头的固有变形大小及分布，因此开发精确计算接头固有变形的方法，并依此建立一个完善的固有变形数据库对于大型复杂结构焊接变形的预测有重要意义。文中提出了几种计算固有变形的方法包括公式法、热弹塑性有限元法、实测法，并分别采用这几种方法对典型T型接头的横向固有收缩与纵向固有收缩进行计算，三种方法得到的结果比较一致。在此基础上，进一步以典型船体结构为研究对象，采用依照这三种方法建立的固有变形数据库对其焊接变形进行预测，并与实测数据进行比较，验证了该数据库的有效性。

Evaluation Method for Inherent Deformation and its Application in Predicting Welding Distortion on Hull Blocks

To predict the welding distortion of large structures using elastic analysis based on the in-herent strain theory, the inherent deformation around the welding line should be evaluated before-hand. The welding residual stress and welding distortion of the welded joint depend on the value and distribution of inherent deformation. Therefore, it is significant to develop methods to evaluate the inherent deformation precisely and establish inherent deformation database for the prediction of welding distortion on large structures. In this paper, three methods (formula method, Thermal-Elas-tic-Plastic Finite Element Method (TEP FEM) and experimental method) for evaluating inherent de-formation are presented. A fillet welded joint is taken as an example, inherent deformations evaluat-ed by these methods are compared. Finally, computations of welding distortion of a typical hull block are conducted based on the inherent deformation database calculated by three methods. By compar-ing the welding distortion of evaluated results with that of measured ones, the reliability of the in-herent deformation database is confirmed.