Influence of Fastening Torque on Fatigue Failure of bolt Joints of Aluminum Alloy Plate

摘要

The influence of the tightening torque on the fatigue life and the failure mode of the bolted specimens were evaluated during the fatigue testing of the aluminum alloy A2024-T3 at different stress amplitudes. In a range of smaller torques, the fatigue life of the bolted specimen increased with increasing tightening torque and the mechanical fatigue failure occurred at the bolt hole edge. At the range of higher torques, the fretting fatigue failure occurred near the bolt hole and the fatigue life decreased with increasing torque. The ultrasonic measurement of the surface acoustic wave was also carried out with the bolted specimen with fastened condition. The reflection from the bolt hole edge and the crack on the fretting surface was observed.