Comfort is one major indicator for passenger vehicle quality. In this context the NVH behavior of brake systems plays an important role to achieve customers’ satisfaction. To evaluate the vibro-acoustic properties of a modern braking system and to manage requirements, advanced measurement techniques are necessary. In addition to classic methods such as acceleration measurement and TPA, the Blocked Forces approach is an option to characterize structure-borne noise introduction. This work explores the blocked forces method for an integrated brake system (IBC). Both, the direct blocked force method and the in-situ blocked force method are compared and evaluated. Advantages and disadvantages are examined, and the limits of the methods are shown. Particularly, the aspect of how these methods can be used without explicit measurements of the entire vehicle plays an important role. On the one hand, this is important so that an optimization of the brake system can be done already at an early stage in the development process. On the other hand, this allows to set vibro-acoustic limits at subsystem level, independently from a vehicle. Finally, it is considered, to what extent this method can be used in combination with simulation techniques to enable an even earlier estimation of the later noise behavior of the system.
Mr. Thomas Vasel, Senior Specialist NVH, ZF Group; Dr. Gerwin Pasch, NVH Engineer, ZF Group; Dr. Nils Perzborn, NVH Manager, ZF Group; Dr. Torsten Treyde, Technical Director Simulation & NVH Div. A, ZF Group