Fatigue life prediction of involute spur gear by finite element method

Gears are vital components of any automobiles, power generation systems and in heavy machinery industries, they need to have good fatigue properties such as fatigue life, endurance limit and fatigue strength for better life and performance of the equipment or machinery. The objective of this study is comparative simulation on zero-based cyclic loading conditions in the fatigue life analysis on general gear materials, and concludes which suits for the better purpose of usage. The Finite Element Method (FEM) has been performed, using ANSYS Workbench 16.2, on the gear models to observe the distribution of stress and life. Comparison was done between Structure steel, Chromium molybdenum Alloy Steel 4130, GG 20 and GG 40. The FEM results of stresses were compared with theoretical results from American Gear Manufacturing Association (AGMA) contact and bending stresses and Hertz contact stress equations. Fatigue life equation derived based on Goodman line theory was used to estimate the minimum gear life using S-N characteristic diagram and FEM for validation purpose. The comparison showed that there is an accepted agreement between the theoretical and FEM results especially in the trend of variation. There is some deviation between the results which may need more effort and modification to decrease this deviation.