铝合金薄板固有变形逆解析方法的研究与开发

Investigation and development of inverse analysis method to estimate inherent deformation of Al-alloy thin-plate joint

为了获得可靠的铝合金焊接接头上固有变形,开发一种将实验与基于固有应变的有限元法(FEM)融为一体的新方法来获得接头的固有变形。为了澄清铝合金薄板焊接固有变形的分布特征,先采用热-弹-塑性有限元计算铝合金TIG重熔接头的焊接变形,并建立固有变形在接头上的简化分布模型。其次,以该模型为基础,提出一种通过测量焊接接头上少数位置上焊前和焊后三维坐标来逆向求解固有变形的计算方法。最后,将利用该算法获得的铝合金薄板接头固有变形代入到基于固有应变理论的弹性有限元分析中,计算得到的焊接变形能较好地再现热-弹-塑性有限元方法计算得到的结果和实验结果。结果表明:采用提出的逆解析方法来获得铝合金接头的固有变形是有效可行的。

An inverse analysis combining experimental measurement and elastic finite element method (FEM) based on inherent strain theory was developed to obtain inherent deformations of Al-alloy joint. Firstly, in order to clarify the feature of inherent deformations in Al-alloy based on the plate joint, the thermal elastic plastic FEM was employed to calculate the welding deformation, and a simplified simple model used to describe inherent deformations was established. Secondly, based on the simplified model, a new method to obtain inherent deformations was proposed through measuring the 3-D coordinates at limited locations before and after welding. Finally, the welding deformation of Al-alloy joint was calculated using the inherent deformations obtained by the inverse analysis, and the results match both the deformation simulated by thermal elastic plastic FEM and the measured data. The results show that it is feasible and effective to obtain inherent deformations of Al-alloy joint using the inverse analysis method.