螺栓连接和拉铆连接在剪切循环荷载作用下的松动行为研究

The Loosening Behavior of Bolted Connection and Riveted Connection Under Cyclic Shear Load

拉铆连接凭借其优秀的防松性能,被应用于越来越多的工程领域。为研究国产新型拉铆钉在剪切循环荷载作用下的松动性能,以应用最为广泛的螺栓连接为对照,分别对规格为8 mm的4.8级普通螺栓、4.8级防松螺栓以及小规格拉铆钉进行剪切循环荷载下的松动试验研究,分析了三类连接在剪切循环荷载作用下的松动过程,研究了荷载幅值和频率对螺栓连接和拉铆连接松动行为的影响。结合微观测试手段分析其损伤形貌,进一步研究剪切循环荷载下螺栓和拉铆钉的防松原理及微动损伤机制。研究表明:在同种工况下拉铆连接的防松性能优于螺栓连接的防松性能;当荷载幅值增大或荷载频率减小时,螺栓连接和拉铆连接的松动程度增大;相较于螺栓,拉铆钉独特的圆弧结构牙型和铆接成型后牙型配合面的过盈配合机制,使其防松性能有明显提升;螺栓与拉铆钉的磨损机制主要是磨粒磨损和疲劳磨损。

With its excellent anti-loosening performance,the riveted connection is used in more and more engineering fields.In order to study the loosening performance of a new domestic rivet under cyclic shear load,this paper takes the most widely used bolt connection as the control,and carries out the loosening test research under cyclic shear load on a common bolt of grade 4.8,4.8 anti-loosening bolt and small-sized pull rivet of size 8 mm,respectively.This paper analyzes the loosening process of the three types of connections under cyclic shear load,and studies the load amplitude and frequency.The effects of load magnitude and frequency on the loosening behavior of bolted and riveted connections were investigated.The damage morphology was analyzed in combination with microscopic test methods to further study the loosening prevention principle and micro-motion damage mechanism of bolts and rivets under cyclic shear loading.The study shows that the anti-loosening performance of riveted connections is better than that of bolted connections under the same working conditions.The loosening of bolted and riveted connections increases when the load amplitude increases or the load frequency decreases.The anti-loosening performance of rivets is significantly improved when compared with that of bolts due to their unique circular structure,and the interference fit mechanism of the mating surface after riveting.The wear mechanisms of bolts and rivets are mainly abrasive wear and fatigue wear.