Effect of a hexagonal rib pattern on the dynamic response of a gearbox housing

Efforts to create lightweight automotive components often result in structures that are more flexible.The use of lightweight gearbox housings for mass-reduction introduces the challenge of an increased dynamic response of the thin housing panels, resulting in higher structure-borne noise. The sound radiation from such lightweight housings can be mitigated using some stiffening measures on the flexible panels. The focus of this paper is to study the stiffening effect of a hexagonal rib pattern on the dynamic response of a gearbox housing. In a Finite Element Method (FEM) study, a simplified model of a gearbox housing is evaluated for its modal properties and equivalent radiated power (ERP) response to bearing-seat excitations. The gearbox housing model is then treated with a hexagonal rib pattern and changes to the modal behaviour and the ERP response are investigated.