Temperature Dependence of Impact Fracture Behavior of Notched Titanium Alloy Bolt for Rocket Fairing Separation

(Part1, Impact Test Using SHPB Method)

Abstract

The payload fairing of the rocket is fixed by a lot of notch bolts. When the rocket reach the outer atmosphere, these notch bolts were fractured by axial impact tensile using explosive device in order to separate the fairing. This impact of separation is problem in satellite-carrying rocket. Thus, it is necessary to clear the mechanism of impact fracture of notched titanium alloy bolt. In this study, the rate and the temperature dependence of tensile deformation fracture in notched titanium alloy bolt were investigated using split Hopkinson pressure bar method. The rate and the temperature dependence of the material strength were confirmed. From the SEM observation results, it was clarified that the fracture surface changed from transgranular into intergranular when the displacement rate was increased and testing temperature was decreased.