Effects of Crack and Structural Flexibility on Planetary Gear System Fault Feature Considering Ring Gear Boundary Condition

•Ring gear boundary condition is considered in dynamic response investigation.•Crack growth test is carried out and theoretical crack morphology is verified.•Crack impact increases with the crack morphology away from the tooth root.•Influence of rim thickness on fault feature is opposite under different boundary conditions.•Decreased housing stiffness reduces the fault feature.