Abstract

The finite element method (FEM) has considerably contributed to the development of advanced manufacturing methods for metal structures. The prediction of the final shape of a component is of great interest to the manufacturing industry. The level of demand may increase due to multistage processes. Therefore, including all steps of the manufacturing chain in the simulations is a key to being successful. This has been done for a long time in the stamping industry, which involves sequences of forming, trimming, and springback. However, more complex manufacturing procedures that include assembling of formed parts with forgings and castings via welding have been modelled with simplifications, resulting in a reduced prediction accuracy. In the present study, a double-curved part manufactured from alloy 718 is formed at 20 °C and laser-welded using the bead-on-plate procedure. The coupling of different manufacturing analyses, including cold forming, trimming, result mapping, welding, cooling, and springback, is achieved using LS-DYNA. Additionally, the effect of adding a damage and failure model in the forming simulation is studied. The results of the forming analysis are used as inputs for the material model *MAT_CWM in the welding simulation. The anisotropic thermomechanical properties of alloy 718 are determined at temperatures up to 1000 °C. Encouraging agreement is found between the model predictions and the results of forming and welding tests. The findings underscore the importance of including the material history and accurate process conditions along the manufacturing chain to both the prediction accuracy of shape distortions, and to the potential of the industry.

中文翻译：

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在合金718中形成和焊接双弯曲带几何形状期间形状变形的预测

摘要

有限元方法（FEM）极大地促进了金属结构的先进制造方法的发展。组件最终形状的预测对于制造业非常重要。由于多阶段流程，需求水平可能会增加。因此，在仿真中包括制造链的所有步骤是成功的关键。在冲压行业中，这已经进行了很长时间，涉及成型，修整和回弹的顺序。然而，已经简化了更复杂的制造程序，包括通过焊接将锻造件和铸件组装在一起的成型零件，从而降低了预测精度。在目前的研究中，在20°C下形成由合金718制成的双曲线零件，并使用板上焊珠工艺进行激光焊接。使用LS-DYNA可以实现包括冷成型，修边，结果映射，焊接，冷却和回弹在内的不同制造分析的耦合。此外，研究了在成形仿真中添加损伤和破坏模型的效果。成形分析的结果在焊接模拟中用作材料模型* MAT_CWM的输入。合金718的各向异性热机械性能是在最高1000°C的温度下确定的。在模型预测与成形和焊接测试结果之间找到令人鼓舞的共识。