Determination of Modal Properties of Automotive Bodies and Frames Using Transient Testing Techniques

This paper describes methods of determining modal stiffness, inertia, and damping properties of automotive bodies and frames using transient testing techniques.

The test equipment described is a digital Fourier analyzer system. The hardware and software used to obtain transfer functions of the vehicle components is discussed, and several examples are presented which compare frequency response data generated by the Fourier analyzer to the same data generated by the more standard sinusoidal excitation methods.