摘要
首次提出了用于汽车生产中分瓣模压印连接接头强度和失效形式的预测方法。根据接头静力学测试中的颈部断裂失效和上下板拉脱失效两种失效形式分别建立了压印接头的两个强度预测公式,2pπ2N N NF A R t t()和2p pπt b s F R,公式以接头颈部厚度Nt和镶嵌量Ut为重要的中间变量。强度预测公式表明:对于颈部断裂的压印接头,颈部厚度值tN越大,接头强度越高;对于拉脱失效的压印接头,接头强度取决于颈部厚度tN和镶嵌量tU,两者之和越大,接头强度越高,并且镶嵌量对接头强度的影响与颈部厚度相比更大。对颈部厚度变化范围为0.35mm^0.56mm、镶嵌量变化范围为0.045mm^0.45mm的15种组合接头,根据强度预测公式计算了接头强度,并进行了拉伸-剪切试验。将计算结果与试验结果进行对比,结果表明二者吻合较好,最大接头强度误差为8.9%。这说明本文建立的接头强度预测公式能够准确地预测压印接头拉伸-剪切过程的强度和破坏形式。
This paper focused on the study of strength and failure mode of clinched joint with segmented die applied in automobile manufacturing industry. A method to predict the strength and failure mode of clinched joint is firstly presented. Two prediction formulas are developed respectively based on the neck fracture mode and button separation failure mode of clinched joints during the static test, which have been defined as functions of the neck-thickness and the undercut. 15 types of clinched joints with different neck-thicknesses(0.35mm^0.56mm) and undercuts(0.045mm^0.45mm) are used to calculate joint strengths with the prediction formulas. Simultaneously, the tensile-shear tests are conducted. Comparison shows that the results from prediction formulas have a good agreement with those from the experiments, and the maximum error of joint strength is 8.9%. The prediction formulas present in this paper can be used to predict the joint strength and failure mode. For the failure mode of neck fracture, joint strength will increase as the neck-thickness increases. For the failure mode of pulled-out separation, joint strength depends on the neck-thickness and the undercut. Joint strength will increase as the combination increases, and the undercut has a greater impact on joint strength than the neck-thickness.
出处
《应用力学学报》
CAS
CSCD
北大核心
2014年第2期299-304,318,共6页
Chinese Journal of Applied Mechanics
基金
国家自然科学基金(50965009)
