Abstract

Determination of sheet metal formability, which is commonly evaluated through a forming limit curve (FLC), is an essential task for part designs in the automotive engineering community. This study provides a coherent comparison among four theoretical FLC criteria including Swift’s instability, Hill’s localized neck, Storen–Rice bifurcation analysis, and Hora’s MMFC. Within these criteria, closed-form solutions for FLC are available for fast and expensiveness explicitly estimating the forming limit diagram (FLD) of sheet metals. According to their closed-form solutions, an empirical suggestion is proposed to improve the accuracy of the theoretical FLC. Quantitative comparisons are then made to evaluate the performance of these criteria for numerous aluminum alloys and steel sheets which are frequently used in automotive industries. Based on the comparisons, the advantages and limitations of each model are discussed from a physical point of view, which appears to be a useful suggestion for selecting a proper theoretical model to evaluate the FLD of sheet metals without conducting experimental tests.

摘要

通常通过成形极限曲线 (FLC) 评估的钣金成形性的确定是汽车工程界零件设计的一项基本任务。本研究提供了四个理论 FLC 标准之间的连贯比较，包括 Swift 的不稳定性、Hill 的局部颈部、Storen-Rice 分岔分析和 Hora 的 MMFC。在这些标准内，FLC 的封闭形式解决方案可用于快速且昂贵地明确估计金属板材的成形极限图 (FLD)。根据他们的封闭形式的解决方案，提出了一个经验建议来提高理论 FLC 的准确性。然后进行定量比较，以评估这些标准对汽车工业中经常使用的大量铝合金和钢板的性能。