高锁螺栓连接件动态拉伸响应与失效机理

飞机坠撞过程中结构的变形模式和吸能对乘员保护具有重要意义，而连接结构的载荷传递和失效形式是影响飞机结构变形的重要因素之一。为了获取航空高锁螺栓连接件在坠撞载荷下的动态响应和失效机理，基于抗剪型平头高锁螺栓设计了2种材料（2024-T3和7050-T7451）的单钉单搭接连接件，利用高速液压伺服材料试验机进行4种速度（0.01、0.10、1.00和3.00 m/s）下的拉伸测试，得到连接件的动态响应、极限载荷、能量吸收和失效模式随速度的变化规律，并分析了连接件的失效机理。结果表明，连接件的失效模式受母材和高锁螺栓/螺母材料强度影响较大，而受加载速度影响较小；当速度从0.01 m/s增加到3.00 m/s时，2024-T3连接件的极限载荷和能量吸收分别增加了2.17%和34.43%，7050-T7451连接件的极限载荷和能量吸收分别增加了5.53%和6.58%。

Dynamic tensile response and failure mechanism of hi-lock bolt joint

The deformation mode and energy absorption property of aircraft sub-structure are of great significance for occupant protection during aircraft crash. The load transfer and failure mode of joint structures are one of important factors affecting aircraft structural deformation. This paper tries to study the dynamic failure behavior of aviation of hi-lock bolt joints under impact loads. Based on the shear resistance hi-lock bolt, the single-bolt single lap joints with two kinds of base metals (2024-T3 and 7050-T7451) were designed. The dynamic tensile tests of the joints were carried out by a high-speed material testing machine under four loading velocities, 0.01、0.10、1.00 and 3.00 m/s. The dynamic response, the ultimate load, the energy absorption and the failure mode of hi-lock bolt joints were measured and analyzed. The results show that the failure mode of the joints is greatly affected by the material strength of the base metal and the high lock bolt / nut, but less affected by the loading speed; as increasing the speed from 0.01 m/s to 3 m/s, the ultimate load and the energy absorption of 2024-T3 joints increase by 2.17% and 34.43% respectively, and the ultimate load and the energy absorption of 7050-T7451 joints increase by 5.53% and 6.58% respectively.