Studying Structure Dynamics with the Cadillac Road Simulator

An automobile structure is a complex, spring-mass system which is excited into various modes of vibration by road inputs. The vibrational modes falling in the frequency range of 5-30 cps are termed structure shake, and produce disturbances seen and felt by the vehicle occupant. The Road Simulator is a four-channel, servo controlled hydraulic exciter system used to simulate road excited structure vibrations in the laboratory. Vertical inputs are provided into the contact patch of each tire to obtain road simulation. The need for such a facility, developing its specifications, problems which had to be overcome, a complete description of the system, and some typical uses are discussed.