等温局部加载成形过程中坯料变厚区过渡条件演化

摘要

采用简单不等厚坯料结合等温局部加载方法，低成本有效地控制大型钛合金筋板类构件成形过程中的材料流动和改善型腔充填。由于倒角过渡形式结构简单、过渡条件范围宽，因此坯料变厚区采用倒角过渡形式较好。局部加载成形过程中的过渡条件演化对坯料变厚区未约束部分的动态边界条件有显著影响。基于合理的假设，应用理论分析建立过渡条件演化模型。应用所建立模型的预测结果与实验和有限元分析结果进行比较，结果表明模型是可靠的。建立的过渡条件演化模型能够很好地处理变厚区未约束部分的动态边界，适用于对多筋构件局部加载成形中材料流动和型腔充填的快速分析。%Using simple unequal-thickness billet combining isothermal local loading can control the metal flow and improve the cavity fill in manufacturing process of large-scale rib-web titanium alloy component with low cost and short cycle. The beveling transition pattern is well used for variable-thickness region of billet (VTRB) due to its simple and ample range of transition condition. The transition condition development in the local loading process has a significant influence on dynamic boundary of unrestricted portion of VTRB. With the help of reasonable assumptions, a mathematical model of transition condition development was established by theoretical analysis. The predicted results for local loading process of rib-web component using the established model were compared with the numerical and experimental ones, and the results indicated that the model of transition condition development is reasonable. Using the established model could deal with the dynamic boundary of unrestricted portion of VTRB well, and the model is suitable for the analysis of metal flow and cavity fill in local loading process of multi-ribs component.