Modelling of nosing for the assembly of aerospace bearings

Abstract

Nosing is a cold metal-forming process, used during the manufacture of self-lubricating plain spherical aerospace bearings. This process ensures the outer bearing ring conforms to the shape of the inner ring, with a central composite liner in-between. Aerospace bearings must be precision engineered due to the large forces and demanding environments they operate within, yet many companies are still heavily reliant on empirical data and experimental methods, however; FEA simulation can be used to predict and characterise complex material behaviour. The nosing process is modelled to predict load history, contact stresses, stress/strain distribution, visual deformation and temperature variation, in order to provide a better understanding of process parameters, tooling design and the resultant forces which are needed for processing. Ultimately, a costly and time-consuming experimental process can be replaced with a virtual rapid one, in order to mitigate defects, secondary processing and low yield rates in production. From initial assessment, a number of objective functions have been identified including geometric conformity, frictional moment and die wear. Theoretical and analytical calculations will be validated against experimental data, both statistically and stochastically, to ensure developed methods are robust. Future emphasis is placed on non-linear friction modelling and strain-rate dependent forming load predictions. © The Society for Experimental Mechanics, Inc. 2013.