Search

• The Johnson-cook damage model, traction separation and Paris law equations are incorporated in the XFEM model to predict the formation of spalling, crack propagation and fatigue life for the spur gear respectively. • 3D finite element analysis was performed to determine the fatigue life of the spur gear using with and without spall using different crack lengths and backup ratio. • Numerical modeling of spur gear developed and results showed that the increase in backup ratio from 0.3 to 3.3, an exponential increase in the fatigue life with and without spall. • The spalling depth obtained on the spur gears with backup ratio 0.3, 0.5, 1.0, and 3.3 are within the range of 20–100 μm. Spur gears are most commonly used to transmit power, and speed variation from one shaft to another shaft. Spalling more frequently occurs surface fault in the gears and sometimes it causes severe damage to the gear tooth. This paper focuses on the effect of spalling on the fatigue life of spur gear. The simulation study is conducted in two parts. In the first part, the Johnson-Cook Damage model is used for the spall generation on the tooth surface. After that, the spalling results are imported as input into the crack initiation /crack propagation model and calculated the rate of crack growth of fatigue crack is based on Paris law implemented in user-defined subroutine Abaqus software. User-defined subroutine code is also validated with the comparison of the numerical and experimental results available in the literature. Cracks with different initial lengths are placed in the deeper cavities of spalling and the crack propagation analysis is conducted using XFEM. The study is conducted for four different backup ratios with cracks of three different initial lengths. The fatigue crack growth life of spur gears is investigated using different crack lengths and backup ratios. Further, a comparison has been made between the fatigue life of a spur having a spalling fault with the fatigue life of spur gear that does not have spalling fault present on its surface. It has also been found in this study that spur gear having cracks originating from the spall region have a less fatigue life as compared to the spur gear without spalling. With the increase in backup ratio from 0.3 to 3.3, an exponential increase in fatigue life is observed. However, the fatigue life of spur gear without the presence of spalling fault has higher fatigue for all backup ratios. [ABSTRACT FROM AUTHOR]