基于修正硬化曲线模型汽车耐撞B柱制造工艺分析

Manufacturing Process Analysis of Automobile Resistant B-Pillar Based on Modified Hardening Curve Model

硬化曲线模型是制造工艺分析的基础,直接影响分析结果的可靠性。基于AutoForm建立B柱可制造工艺分析模型,采用传统经典硬化曲线模型,获取成形后的应变分布和减薄率分布,并与实际冲压零件进行对比,选取10个位置点对比减薄率的差异;选取强度不同的4种材料,对比相同Ludwik硬化模型下的精度差别;针对高强度钢提出了一种修正硬化曲线修正模型,采用最小二乘法获取强度级别较高的两种材料的模型,获取曲线的拟合精度;采用修正模型,对B柱的可制造性进行分析,与传统模型结果、实测结果进行误差对比分析,以检验模型的精度。结果可知,采用传统模型获得的最大减薄率与实际测试结果相差较大,达到38.30%;采用修正模型获得的减薄率,由传统模型的18.8%增加到24.6%,而实测结果为26%,之间的误差则由原来的38.3%降低到5.68%,所有测点的减薄率与实测值之间的误差均控制在6%以内,与传统模型相比得到了很大的提升,且最大位置点也保持一致;表明修正模型能够更好地反应高强钢材料的硬化过程,与实际值之间的贴合度较高,可以作为设计分析的参考依据。

Hardening curve model is the basis of manufacturing process analysis,which directly affects the reliability of analysis results.The B-pillar manufacturable process analysis model was established based on AutoForm.The strain distribution and thin-ning rate distribution after forming were obtained by using the traditional classical hardening curve model,and compared with the actual stamping parts.10 position points were selected to compare the difference of thinning rate.Four materials with different strength were selected to compare the accuracy difference under the same Ludvik hardening model.A modified hardening curve model for high strength steel was proposed.The model of two materials with higher strength level was obtained by least square method to obtain the fitting accuracy of the curve.The manufacturability of B-pillar was analyzed by using the modified model,and the error was compared with the traditional model results and measured results to test the accuracy of the model.The results show that:the maximum thinning rate obtained by using the traditional model is quite different from the actual test results,up to 38.30%.The thinning rate obtained by using the modified model is increased from 18.8%of the traditional model to 24.6%,while the measured result is 26%,and the error between the thinning rate and the measured value is reduced from 38.3%to 5.68%.The error between the thinning rate of all measuring points and the measured value is controlled within 6%,which is greatly improved compared with the traditional model,and the maximum position point is also consistent.It shows that the modi-fied model can better reflect the hardening process of high-strength steel materials,and has a high fit with the actual value,which can be used as a reference for design and analysis.