Vibration hypersensitivity causes detection in finite elements models
Résumé
This paper deals with uncertainties analysis. The objective is to detect structural zones producing hypersensitive vibration behavior. Many industrial products, because of production and assembly lines, present small differences in parameters values, which can sometimes induce large distortions as far as the radiated sound is concerned. On the basis of our previous works [1], we present here a FEM application of a method that allows one to detect structural zones producing hypersensitive behavior. The concept is quite simple, and is cheaper than Monte Carlo simulations. The complete resolution of the problem is done only once, using nominal parameters of the structure, in order to obtain the displacement field. In our case, a finite element analysis is performed on a typical hypersensitive structure, and modal deformations are determined on the particular nominal structure. Then, considering another structure, built using variable parameters, chosen in a random way in the acceptable manufacturing range, the finite element assembly procedure is performed. These matrices are finally used to define an indicator in which the displacement field of the nominal solution permits to detect structural zones responsible for hypersensitive behavior. It is based on the computation of energy of a residual displacement field. After a presentation of the basis of this tool, numerical results are presented on a finite element model of a plates network and on an industral cross member beam.