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

Abstract

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.