Static and Dynamic Test Data Combined with Analytical Models.

Abstract

Practical applications of updating techniques using measured normal mode parameters or mobility measurements document the advantages and future prospects of the updating technique, but also show the difficulties and problems for practical applications. These insufficiencies are mainly based on the limited number of measured normal modes and measured deformations compared to the large amount of stiffness and mass data of the finite element model. Moreover, the measured normal modes must not show elastic deformations on all substructures or coupling elements. However, modal synthesis technique requires accurate coupling stiffnesses to obtain reliable results. Interface loading may be one way to simulate dynamic loads at the coupling points, but this also has disadvantages caused by the interface loading structure. Another possible method of obtaining the required stiffness information of critical structural components is to perform aimed static deformation measurements. The combination of both static and dynamic test data enlarges the test information. This paper describes the formulation of an updating procedure which uses static and dynamic test data simultaneously. The updating results of a simulated eleven degree of freedom system and of a simple real structure (sandwich plate) show the performance of the proposed technique.