组合热源模型下焊剂片约束电弧焊温度场预测

通过反演法将高斯面热源与柱型体热源耦合构建成组合热源,再运用软件ABAQUS对焊剂片约束电弧焊高强钢T形接头在此组合热源作用下形成的温度场进行数值模拟.模拟过程中着重考虑了夹具与工件之间的接触传热.通过将模拟结果与实验结果对比,发现模拟与实验所得焊缝形貌、以及各测试点焊接热循环曲线基本吻合,从而验证了有限元分析中使用该组合热源模型预测焊剂片约束电弧焊温度场的可行性和有效性.对T形接头温度场分布研究发现,模拟的T形接头的面板和芯板在厚度方向温度分布均匀.对热循环曲线的分析中发现,夹具在工件冷却阶段的作用明显,为此对焊接热影响区范围进行数值预测,预测结果与实验结果吻合.

Prediction on flux bands constrained arc welding process based on a hybrid heating source model

By means of software ABAQUS, a hybrid heating model coupled by a Gaussian face heat source and cylindrical volume heat source is established to analysis characteristics of welding-induced temperature distribution during the process of the flux band constrained arc T-joint welding. The thermal contact conductance between the fixture and work piece has been taken into account emphatically in the model during simulation. By comparing results from simulation with those from experiments, it is found that weld morphology and thermal cycle curves of each testing point in welding are basically consistent with experimental results. Thus, it is verified that the hybrid heat source model utilized in finite element analyses is feasible and effective to predict the temperature field of the flux band constrained arc T-joint welding. In the study of temperature field distribution of the T-joint, it is also found that the temperature distribution in panel plate and core plate of the simulated T-joint becomes uniform in direction of plate thickness. In the analysis of the thermal cycle curves, it is further found that the fixture plays an apparent role in cooling stage of the workpiece. The range of welding HAZ is then predicted numerically further in this case. The predicted results are consistent with our experimental ones.