A mode-based meta-model for the frequency response func- tions of uncertain structural systems

Frequency response functions (FRFs) play an important role in the assessment of the structural response of linear systems subjected to dynamic forces. In this work a meta-model is presented to approximate the eigenfrequencies and mode shapes to describe the FRFs. The meta-model is supposed to provide a computa- tionally fast solution for the eigenvalue problem, which needs to be solved for each set of random structural input parameters. The provided relations can be helpful in the design stage to control the dynamic response within certain frequency bands. Moreover, the meta-model can be used for optimization and reliability as- sessments based on Monte Carlo sampling procedures. Numerical examples show the application of the method focusing mainly on the variability of the FRFs w.r.t. the number of random variables involved to model the mechanical system. The accuracy of the meta-model to approximate FRFs is assessed by a com- parison with the solution by Finite Element (FE) analyses.