材料期刊网

本文的研究目的是分析三层板不同搭接方式的压印接头的力学性能，主要采用试验方法对其进行研究，具体方法如下：首先对1．5 mmAA5052＋1．5 mmSPCC＋1．5 mmAA5052三层板不同配置方式下的压印接头进行静态力学性能测试，分析三层板压印接头的静态失效模式及其静强度；再对静态力学性能最优组进行动态疲劳性能测试，分析疲劳失效模式及其疲劳强度，并采用最小二乘法拟合获得接头力－寿命（ F－N）方程．试验结果表明：静态失效为上板颈部断裂、中板内锁拉脱和混合失效三种模式；T－A型接头静强度最低，T－C型接头静强度最高．其中，T－C型接头疲劳失效模式为上板颈部先断裂，之后下板出现裂纹导致接头失效；T－C型接头上板颈部疲劳性能较差，当应力水平为静强度40％时，疲劳循环最多只能达到15965次，但是中板与下板连接可达到200万次．

This paper is concerning the effect of specimen configuration on the static mechanical behavior of clinched joints, three?layer joints in 1.5mmAA5052+1.5mmSPCC+1.5mmAA5052 were conducted. It indicated that the specimen configuration had a significant effect on the failure modes and static strength of three?layer clinched joints. The fatigue behavior of the specimens, which had the optimum static performance, has been investigated experimentally. The least square method was used to obtain the load?life (F-N) equations. Results reveal that three failure modes, fracture in the neck of upper sheet, interlock failure in the middle sheet and mixed failure, were presented in the static testing. Clinched joints in T-A type owned the lowest static strength;while clinched joints in T-C type had the highest static strength. The neck facture of the upper sheet of the clinched joints in T-C type occur initially in fatigue testing, and then cracks appeared on the bottom sheet. The clinched joints had a weak fatigue performance on the neck of the upper sheet. The fatigue cycle of the neck of upper sheet is only around 10 thousands when maximum fatigue load is 40%of the static strength;but the fatigue cycle of the connection between middle sheet and bottom sheet can reach 2 millions.