ABSTRACT:
The turbine blade-disc joints in a jet engine often fail prematurely against predicted life due to fretting. Fretting and fatigue related failures are around 70-80% of total mechanical failure. This paper presents the simulation of the effect of coefficient of friction, rotational speed on fretting fatigue of dovetail joint attached with retaining pin. Contact pressure and sliding distance influences the fretting phenomenon. Higher the values of contact pressure and sliding distance higher will be the fretting phenomenon. The dovetail interface was modeled using Unigraphics-8 software and nonlinear static structural analysis was performed in ANSYS WORKBENCH 15.0. The analysis was performed at rotational speeds ranging from 2000 rpm to 10,000 rpm and coefficient of friction was varied from 0.1 to 0.3. From the simulation it was observed that, the peak contact pressure reduced by 30% and 10% for straight and skew dovetail joint respectively by increasing COF from 0.1 to 0.3. The sliding distance reduced by 26% and 39% for straight and skew dovetail joint respectively by increasing COF from 0.1 to 0.3. From the simulation the fretting wear index for the given condition was 1.25 for straight dovetail joint and 6.009 for the skew dovetail joint. Higher fretting wear index indicate higher fretting damage in the joint.