汽车板成形极限预测公式研究

RESEARCH ON THE FORMULA FOR PREDICTING THE FORMING LIMIT OF AUTOMOTIVE SHEET METAL

成形极限作为汽车板关键性能指标和零件变形失效的评价准则,在汽车零部件加工产业链中发挥着重要作用。基于成形极限预测公式,可以根据材料的常规力学性能指标,快速得到成形极限,避免繁琐耗时的检测实验,为钢铁材料企业利用大生产检测得到产品成形极限指标提供重要理论和工具支撑。分析了国外学者提出的成形极限关键指标FLC_(0)的预测公式,对3种公式因计算结果差异导致评价准则不一致的问题,开展了22种汽车板产品成形极限检测,提出了根据FLC_(0)进行成形极限预测精度对比的分析方法。在完成单轴拉伸力学性能测试基础上,依据Keeler、Cayssials和Abspoel 3种预测公式得到FLC_(0)计算结果,对比分析得到3种公式的整体精度和适用的具体产品类别。研究结果显示,22种常用汽车板产品实测FLC_(0)与采用预测公式计算结果存在较高的相关性,但3种预测公式针对成形极限的预测结果差异明显,且由于公式采用的性能指标差异,导致各公式的整体通用性和具体汽车板产品的适用性均有所不同。

As a key performance indicator of automotive panels and an evaluation criterion for part deformation failure,forming limit plays an important role in the automotive component processing industry chain.Based on the prediction formula of forming limit,the forming limit can be quickly obtained based on the conventional mechanical performance indicators of materials,avoiding tedious and time-consuming testing experiments.This provides important theoretical and tool support for steel material enterprises to use the large-scale production testing to obtain forming limit indicators.An analysis was conducted on the prediction formula for the key indicator FLC_(0) of product forming limit proposed by foreign scholars.To address the issue of inconsistent evaluation criteria due to differences in calculation results among three formulas,22 types of automotive sheet metal products were tested for forming limit,and an analysis method for comparing the accuracy of forming limit prediction based on FLC_(0) was proposed.Based on the completion of uniaxial tensile mechanical performance testing,the FLC_(0) calculation results were obtained using three prediction formulas:Keeler,Cayssials,and Abspoel.The overall accuracy and specific product categories applicable to the three formulas were compared and analyzed.The research results show that there is a high correlation between the measured FLC_(0) of 22 commonly used automotive panel products and the calculated results using prediction formulas.However,there are significant differences in the prediction results of the forming limit among the three prediction formulas,and due to the differences in performance indicators used in the formulas,the overall universality of each formula and the applicability of specific automotive panel products are different.