Abstract
Four and Seven Post Rig tests continue to be an engineering tool widely used by Racing Teams, Chassis Manufacturers, and OEM Companies around the globe. Its advantages include the possibility of validating the results obtained by simulated multi-body systems software applications on the real vehicle, durability testing, NVH, and performance evaluation and development for Motorsport applications between others. This paper will focus its attention on the latest, addressing the incoherency that sometimes occurs between the trends of optimisation of damping set-up obtained by swept sine (chirp) test signals and track drive file test signals, obtained from track testing.
Assessment of vehicle grip is obtained by analysing the variation of the Contact Patch Load during a reproduction of a lap of a specific track on the rig. This same analysis is also commonly performed for swept sine tests. The problem addressed by this work consists of studying and proposing a solution for the differences in the trends that sometimes results between these tests, indicating a difference in response from the vehicle. Problable due to the non-linearities within the suspension system, most notably the dampers. The results given show that it is possible to produce similar vehicle motions using swept sine testing but the spectral characteristics of the sweep need to be shaped. This work finishes with a discussion of the experimental results obtained, recommendations for testing and conclusions.
Keywords: Suspension Testing, Four and Seven Post Rigs, Motorsport, Track Drive Files, Frequency Sweeps.