铝合金焊接结构塑性变形及断裂失效预测方法

Plastic Deformation and Failure Prediction of Aluminum Alloy Welded Structures

铝合金焊接接头力学性能不均匀加大了焊接结构变形及开裂失效预测的难度。通过特殊样件拉伸试验,结合有限元反求方法获得了铝合金焊接接头焊缝、热影响区局部材料参数,建立从细观损伤力学角度预测铝合金焊接结构变形开裂的GTN(Gurson-Tvergaard-Needlemen)损伤模型。将焊接接头按照材料性能差异进行分区,构建精细有限元模型,采用Ls-dyna软件结合GTN损伤模型对铝合金拼焊薄壁梁结构轴向压溃变形及开裂失效进行了预测,预测结果与试验吻合很好,验证了该方法的有效性。

The inhomogeneous mechanical properties of aluminum alloy welded joints increase the difficulty in predicting the deformation and failure of the welded structures. The local material parameters for the welds and heat-affected zone of aluminum welded joints were obtained by the special sample tensile test combined with the inverse finite element method. The GTN damage model was established to predict the deformation and fracture of welded aluminum structures from the perspective of damage mechanics in mesoscopic scales. The software Ls-dyna combined with the GTN damage model was used to predict the axial compressive deformation and fracture of the welded aluminum structure. The predictions are compared with the experimental results to validate the effectiveness of the method.