Finite elements modelling of rotor flapping mass

In the frame of increasing flight safety, finite element models are developed to computethe stresses in critical parts. The results obtained often complete the ones derived from fullscale experimental tests and analytical estimations. A finite element model is particularlyuseful to simulate many different flight configurations that can not be tested experimentally.This paper presents the different stages in the development of a finite element model ofa rotor flapping mass. On a helicopter the flapping mass makes the connection betweenblades and rotor hub. This study particularly focuses on the estimation of the fatiguelimit of a composite component. This component, called roving winding, is particularlycritical as it sustains most of the loads applied on the flapping mass. Getting an accuraterepresentation of the stress distribution in the roving was the main objective. The resultsderived from the model presented here were compared to experimental ones to ensure itsaccuracy. The confidence in the model obtained makes possible its use to evaluate theimpact of some material change or geometry modifications. The model also permitted toevaluate the impact of some productions defects on a composite part