超声振动辅助铆接精确成形

Accurate forming on riveting assisted by ultrasonic vibration

采用超声振动辅助技术,利用万能材料试验机分别对45钢、6063铝合金和T2铜3种板材进行铆接实验。在不同条件下,对铆接过程中的压铆力、剪切强度、相对干涉量以及6063铝合金铆钉的材料流动进行分析,研究了超声振动对铆接工艺中铆钉的力学性能、变形行为以及铆接质量的影响。结果表明:施加超声振动时,随振幅增大,压铆载荷逐渐降低,不同板材的压铆力的降幅基本相等;剪切强度得到了提升,最大增幅为10.47%。在超声振动的表面效应和软化作用下,接触面之间的摩擦作用得到改善,难变形区面积减小了51.08%,钉杆的变形尺寸更加均匀。超声振动可降低铆接结构的相对干涉量系数,尺寸均匀度的改善有利于延长铆接结构的疲劳寿命。

Riveting experiments were conducted on three kinds of plates,such as 45 steel,6063 aluminum alloy and T2 copper by the universal material testing machine using ultrasonic vibration assist technology.Then,the riveting force,shear strength and relative interference amount as well as material flow of 6063 aluminum alloy rivets during the riveting process were analyzed under different conditions,and the influences of ultrasonic vibration on mechanical properties,deformation behavior and riveting quality of rivets during the riveting process were investigated.The results show that the riveting load decreases gradually with the increasing of amplitude when applying ultrasonic vibration,the reduction of riveting force for different plates are basically the same,and the shear strength is enhanced with the maximum increase of 10.47%.Under the surface effect and softening action of ultrasonic vibration,the friction effect between contact surfaces is significantly improved,the area of difficult deformation zone is reduced by 51.08%,and the deformation size of nail rod is more uniform.Thus,the ultrasonic vibration reduces the relative interference amount coefficient of riveted structures,and the improvement of dimensional uniformity is beneficial to prolong the fatigue life of riveted structure.