Dual Input Estimation of Frequency Response Functions for Automotive Structures

The accurate measurement of the frequency response function is vital to the estimation of the system modal parameters. The use of the single input/output theory to formulate the equations for the frequency response function can be replaced by an equivalent theory involving multiple inputs. The results of this approach provide frequency response functions that are comparable to the single input/output case but with a reduction in the time required per measurement and an increase in the consistency of modal frequency and damping values estimated from different frequency response functions. Examples are included for representative automotive structures.