Study on the gear fatigue behavior considering the effect of residual stress based on the continuum damage approach

Abstract The fatigue failures of gears have great influence on the lifetime and reliabilities of mechanical transmission systems. Initial residual stress (IRS) induced in the manufacturing process, together with the applied loading stress, contributes to the gear fatigue behavior. Gear fatigue behavior represents a continuous damaging process during a high-cycle period. In the present work, a damage-coupled elastic-plastic numerical model considering the effect of IRS is developed to investigate the gear fatigue performance. The deterioration of the gear material, the detailed evolution of damage and the stress response during the cyclic loading process are calculated and recorded based on the continuum damage mechanics (CDM) using a user material subroutine (UMAT) in ABAQUS. Both the tooth surface contact fatigue and tooth root bending fatigue of the gear are evaluated, and the influence of IRS on the stress response and damage evolution is analyzed. Results show that the risk of surface contact fatigue failure of this gear is much greater than that of the tooth bending fatigue. The initial compressive residual stress has positive effect on the contact fatigue performance while the initial tensile residual stress with the amplitude of 380 MPa would reduce the gear contact fatigue life by 20%.