A computational model of the fatigue crack initiation period on the helical gears
,with consideration of the heat treatment by carburization and friction effects, is presented.
In order to calculate the number of stress cycles required for the appe
arance of the initial
cracks, and study the influence of dynamic behavior. For this end, a dynamic model of gear
with two freedom degrees in torsion developed in Matlab and fatigue criteria are used. The
computational results are compared with those obtained using strain- life method. The
obtained results show that appearance of initial fatigue crack depends strongly on the
friction coefficient between the surfaces, heat treatment, and on the dynamic load.