Estimation of structural damping using an expansion in the Chebyshev orthogonal basis
Résumé
The aim of this study is to estimate structural parameters such as material properties (density, Young Modulus...) or geometrical properties (inertia, cross-section...) and structural damping. The identification method is based on a three steps process. Firstly, the recorded displacement field is recorded an expanded on the Chebyshev orthogonal basis. Thanks to this expansion the partial derivatives of the signal are computed. Finally, the partial derivatives are used to reconstruct the partial differential equation of motion of the structure. The three steps process will be directly illustrated by an example, even if this method could be applied to any kind of structure. The example is a simply-supported bar. The free response of this bar is the input signal used in our identification process. The identification process will be tested by simulation in noisy condition through a Monte Carlo test. The influence of the truncation order and the wave number will be discussed. With 5% of noise the structural damping is estimated with an error smaller than 0.001%