resonance frequency or mass) as a result of modifying a parameter value.
The coefficients obtained for all combinations of responses and parameters are stored in a sensitivity matrix.
Other examples are a launcher tested with different levels of fuel, or differently shaped test specimens made of a composite material that needs to be identified.
From measured harmonic operational shapes, and an updated finite element model, a system of equations can be solved to obtain the excitation forces.
When working with large FE models, a bottom-up modeling, testing and assembly approach should be considered.
Parameters that can be updated are all mass, stiffness and damping properties used in the definition of the FE model.This provides a richer set of test data to serve as reference for updating element properties that are common in all configurations.Such properties can be, for example, the joint stiffness or material properties.The resulting FE model can be used for further structural analysis with much more confidence.Example applications are FE model validation and refinement, material identification from vibration testing, FE model reduction, damage detection, ...