Effect of torsion angle on tension-torsion multiaxial fretting fatigue behaviors of steel wires

Abstract A tension-torsion multiaxial fretting fatigue test apparatus was employed to investigate the effect of torsion angle on multiaxial fretting fatigue behaviors of steel wires in the present study. Working principals and structures of the test apparatus were introduced. Evolutions with fatigue loading of hysteresis loops of tangential force versus relative displacement between contacting wires, and torque versus torsion angle of steel wire were explored. Three-dimensional white light interferometer was used to measure the deflection angle and size of wear scar. Coefficients of friction during tests at distinct torsion angles were compared. Crack propagation characteristics of steel wires were explored employing the X-ray computed tomography. The results show that both types of hysteresis loops present overall increased loop areas with increasing torsion angle. An increase of torsion angle induces increased deflection angle and size of wear scar, coefficient of friction and maximum crack depth of steel wire, which reveals accelerated multiaxial fretting fatigue damage.