Analysis of mode shape variations using response surface methodology

This paper addresses to the analysis of mode shape of a structure affected by parameter modification. Using approximating techniques it is possible to express the eigenvectors in terms of structural parameters of the studied model and follow the mode shape changes when a perturbation of those parameters is imposed. The result is a modeling of the eigenvectors that allows to quickly perform several analyses of the vibrating structure. However, during the modeling phase not-trivial problems could raise from the eigenvector scalability or from physical phenomena like mode swapping and mode veering. The paper, after a description of the implemented methodology, shows the results from a series of Monte Carlo Simulations that have been carried out in order to figure out the MAC and node lines dispersion.