Localization of structural zones producing hypersensitive behavior: finite element approach

On the basis of our previous works [J. Sound Vib. 260 (1) (2003) 83], one 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. 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 hypersensitive plates network, in which sensitivity problems are linked to angular coupling, and on a cross member beam, which is made up of three spot-welded layers. (C) 2003 Elsevier B.V. All rights reserved.