铝蜂窝的电阻点焊工艺及其结构的压缩性能

发布时间：2018-09-03 07:15

【摘要】：本文以蜂窝吸能结构件为应用需求背景,研究了铝蜂窝的电阻点焊制备工艺,制备了点焊方形铝蜂窝结构单元试样,在不同温度条件下测试了试样的轴向准静态压缩性能,与相同规格的胶接铝蜂窝结构试样的准静态压缩试验结果进行了对比,探究点焊方形铝蜂窝结构单元试样的性能特性;同时采用Abaqus有限元模拟电阻点焊铝蜂窝结构单元的轴向压缩行为,观察分析了铝蜂窝壁板变形及焊点周围的应力分布状态。通过焊点熔池微观形貌的观察及焊点剪切力的测定确定了铝蜂窝电阻点焊的优化工艺参数(焊接电压为250V、焊接时间为1.4s、电极压力为60N),单个焊点的剪切力达到66.5N,正拉力达到30.9N。铝蜂窝结构单元试样的压缩应力应变曲线分线弹性变形、初始峰值屈服、稳定屈服平台和密实化四个阶段。通过改变焊点数目制备不同焊点距的铝蜂窝进行准静态压缩试验发现,铝蜂窝压缩的稳定屈服平台应力随着焊点距减小而增大,而焊点距对铝蜂窝的初始峰值屈服强度没有明显影响。电阻点焊铝蜂窝对环境温度的敏感性较小,从-50°C升至100°C,电阻点焊铝蜂窝的初始峰值屈服强度降低9.02%,胶接铝蜂窝的初始峰值屈服强度降低38.97%。通过电阻点焊铝蜂窝结构单元试样的压缩过程观察和有限元模拟,蜂窝的初始屈服堆叠发生在结构的端部,随后依次扩展,铝蜂窝结构焊点附近没有明显的应力集中。
[Abstract]:In this paper, based on the application requirement of honeycomb energy absorption structure, the fabrication process of aluminum honeycomb resistance spot welding is studied, and the specimen of square aluminum honeycomb structure unit is prepared. The axial quasi-static compressive properties of the sample are tested at different temperatures. Compared with the quasi static compression test results of adhesive aluminum honeycomb structure specimens of the same size, the performance characteristics of spot welded square aluminum honeycomb structural units were investigated. At the same time, the axial compression behavior of resistance spot welding aluminum honeycomb structure element was simulated by Abaqus finite element method, and the deformation of aluminum honeycomb panel and the stress distribution around the solder joint were observed and analyzed. The optimum technological parameters of aluminum honeycomb resistance spot welding (welding voltage 250V, welding time 1.4s, electrode pressure 60N) were determined by observing the microstructure of weld pool and measuring the shear force of solder joint. The shear force and positive tensile force of single solder joint were 66.5 N and 30.9 N respectively. The compression stress-strain curves of aluminum honeycomb element specimens are divided into four stages: linear elastic deformation, initial peak yield, stable yield platform and compaction. By changing the number of solder joints to prepare aluminum honeycomb with different solder joint spacing, the quasi-static compression test shows that the stable yield platform stress of aluminum honeycomb compression increases with the decrease of solder joint distance. However, the solder joint distance has no significant effect on the initial peak yield strength of aluminum honeycomb. The sensitivity of resistance spot welding aluminum honeycomb to ambient temperature is less, from -50 掳C to 100 掳C, the initial peak yield strength of resistance spot welding aluminum honeycomb decreases 9.02 and the initial peak yield strength of adhesive aluminum honeycomb decreases 38.97. Based on the observation of compression process and finite element simulation of aluminum honeycomb structural unit specimen by resistance spot welding, the initial yield stacking of honeycomb occurs at the end of the structure, and then expands in turn, and there is no obvious stress concentration near the solder joint of aluminum honeycomb structure.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG453.9

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