In this research, the failure of a stud bolt was studied. This bolt is under periodic loading, in a multi-stage compressor. The undesired vibration of the system causes vibration load on the bolt. The bolt was modeled in Abaqus software and the generated stress was calculated. To determine the dynamic load on the bolt, the vibration of the system was measured by a digital vibration sensor and this load was simulated in Abaqus software. The boundary condition and loading were considered similar to the real working condition. The failure and fatigue of the bolt was investigated in the periodic loading. The factors such as the shank diameter, chamfer radius and material were changed and the corresponding response of sample and change in stress was studied. The most probable points of the bolt for failure were found and the effected of the reduced shank diameter on its life was considered. In the initial design, the shank diameter was considered 12 mm. The results shown that by decreasing the shank diameter, the stress first decreases and then increases and the minimum of stress occur at the shank with a diameter of 11.47 mm. Also, by increasing the chamfer radius, the stress first increases and then decreases and the minimum of stress occurs at the chamfer radius of 33 mm. تفاصيل المقالة