Reasons for installation fracture of TB8 titanium alloy high lock bolt

The fracture of a TB8 titanium alloy high lock bolt occurred during the assembly process. The fracture causes were analyzed by means of macroscopic observation, fracture analysis, metallographic examination and mechanical property test. The results show that during the installation process, the bolt was subjected to additional bending stress due to different axes of the bolt and the installation hole. Under the combined action of external bending stress and axial load, the bolt was overloaded and fractured. In order to further verified the influence of different axes of the bolt and the installation hole on the failure tensile force of the bolt, the tensile test scheme of placing different inclined gaskets under the bolt head was designed. It was concluded that the failure tensile force of the bolt decreased gradually with the increase of the inclination.