结构胶对钢铝自冲铆接接头力学性能的影响

Influence of structural adhesive on mechanical properties of steel-aluminum self-piercing riveted joints

为研究结构胶对钢铝自冲铆接静力学性能的影响,制作了具有自冲铆接、胶接和胶铆复合3种连接方式,且搭接距离分别为15、20、25、30和35 mm的接头,进行拉伸试验和失效形式分析。结果表明:对比自冲铆接接头和胶接接头,胶铆复合接头铆钉成形质量优于铆接接头,胶铆复合接头胶层厚度小于胶接接头。在相同搭接距离下,胶铆复合接头的力学性能优于铆接接头和胶接接头。搭接距离为20 mm时,拉剪强度增幅为15.3%,静强度增幅为30.1%。搭接距离超过20 mm时,随着搭接距离增加,胶铆复合接头拉伸强度提高,拉剪强度降低且胶铆复合接头与胶接接头的能量吸收差值逐渐减小,表明胶铆复合接头中胶层承受了主要载荷,铆接对胶铆复合接头强度的影响逐渐减小。胶铆复合接头的失效形式为铆钉的拉脱、胶层的内聚失效和界面失效。

To study the influence of structural adhesives on the static properties of steel-aluminum self-piercing riveting,three kinds of joints were made,including self-piercing riveting,adhesive bonding,composite riveting and adhesive bonding,and the lap distance was 15,20,25,30 and 35 mm respectively.The tensile test and failure mode analysis were carried out.The results show that compared with self-piercing riveted joint and adhesive joint,the forming quality of composite riveted and adhesive bonding joint is better than that of riveted joint,and the thickness of adhesive layer of composite riveted and adhesive joint is less than that of adhesive joint.At the same lap distance,the mechanical properties of composite riveted and adhesive bonding joints are better than those of riveted joints and adhesive joints.When the lap distance is 20 mm,the tensile shear strength increases by 15.3%,and the static strength increases by 30.1%.When the lap distance is more than 20 mm,with the increase of lap distance,the tensile strength of composite riveted and adhesive bonding joint increases,the tensile shear strength decreases,and the difference of energy absorption between composite riveted and adhesive bonding joint and adhesive bonding joint decreases,which indicates that the adhesive layer bears the main load,and the influence of riveting on the strength of composite riveting and adhesive bonding joint decreases gradually.The failure modes of the composite riveting and adhesive bonding joint are the pulling off of the rivet,the cohesive failure of the adhesive layer and the interface failure.