三明治结构自冲铆接头力学性能及失效模式分析

为了探究泡沫金属夹层对自冲铆接头抗压能力和抗剪能力的影响，分别使用1 mm泡沫铜和泡沫铁镍作为夹层制作单搭和十字搭自冲铆接头，使用MTS拉伸试验机对试件进行拉剪和剥离试验，对比接头的力学性能，使用电子扫描显微镜对十字搭泡沫铁镍夹层接头拉脱区进行分析。结果表明: 5052-泡沫铜-5052接头的失效载荷和能量吸收值均小于相同搭接形式的5052-泡沫铁镍-5052接头；单搭接头下板拉伸方向的铆扣几乎不撕裂，朝向两端的撕裂逐渐加剧，泡沫铁镍夹层接头下板与铆钉中心线重合的位置发生断裂；十字搭接头失效模式为铆钉先变形挤压下板，再撕裂铆扣处面板脱出，钉脚经过夹层挤压的地方时刮擦突出的金属表面。

Analysis of Mechanical Properties and Failure Modes of Sandwich Structure Self-Piercing Riveting Joint

In order to study the influence of different foam metal interlayers on the compressive and shear resistance of self-piercing riveted joints, 1 mm foam copper and foamed iron nickel were used to make the same type of aluminum alloy single and cross self-piercing riveting joints. The MTS tensile testing machine was used to perform tensile shear and stripping tests on the specimens. Comparing the mechanical properties of the joints, and analyzes the pull-out zone of the cross-linked foamed iron-nickel sandwich joint with an electron scanning microscope. The results show that the failure load value and energy absorption value of the 5052-foam copper-5052 joint are smaller than the 5052-foam iron-nickel-5052 joint of the same lap type. The rivets in the tensile direction of the lower plate of the single-lap joint hardly tear, and the tears towards the ends gradually increase. The position where the lower plate of the foamed iron-nickel sandwich joint coincides with the center line of the rivet fracture. the failure mode of the cross-lap joint is that the rivet deforms and squeezes the lower plate first, then tears the panel. When passing through a place squeezed by a sandwich, the protruding metal surface is scratched.