Investigation of dynamic stress recovery in elastic gear simulations using different reduction techniques

摘要

Stresses in gear contact simulations, performed using elastic multibody systems, are recovered. A single gear pair is used for stress investigations and an impact is chosen as simulation case representing an extremely dynamical situation. The gears are modeled as a reduced elastic multibody system allowing a fast computation of the dynamical problem. Depending on the projection matrix which is used for model order reduction, stresses can sometimes not be recovered accurately throughout the whole gear. Thus, the main focus in this paper lies on the selection of the functions which make up the projection matrix and, therefore, determine the elastic deformations and the quality of recovered stresses. However, the chosen set of modes does not only affect stress calculation, it also strongly affects the computation of the dynamics of the gear system and, thus, the computational effort, and may lead to serious drawbacks. This issue is discussed, too. Upon that, several different mode sets are analyzed trying to minimize the computational effort of the elastic multibody system for the given problem while still being able to recover accurate stress values on distinct geometric areas. The stress values are compared with a finite element reference computation. The novel contribution of this paper is the determination of a minimal set of modes including ones assigned to the nodes of the gear contact surface, which are able to accurately recover stresses but minimize the numerical drawbacks.