Eigensolutions sensitivity analysis using a sub-structuring method

• Published in: Computers & structures 1999-05, Vol.71 (3), p.257-265
• Main Authors: Lallemand, B., Level, P., Duveau, H., Mahieux, B.
• Format: Article
• Language: English
• Subjects: Complex structures; Mass optimization; Sub-structuring
• ISSN: 0045-7949; 1879-2243
• DOI: 10.1016/S0045-7949(98)00231-4

The sub-structuring methods often prove to be the best and sometimes the only strategy for the analysis of complex structures. With the improvement of computational capacities, the use of these methods is currently justified by the presence of organization constraints of large-scale projects as part of simultaneous engineering approaches. The modal synthesis computation tool offers the flexibility required so as to anticipate the vibratory behaviour of the complex structure in the design process. It is easy to take into account the successive modification involved in various elements optimization, to computationally characterize the modal behaviour of the substructures according to their fulfilment level. The classical optimization of such structures, taken as a whole, requires on the one hand a finite element analysis allowing calculation of the structure design at the current point, and on the other hand a parametric sensitivities computation in order to set up the design variables to optimize. The use of an optimization approach of a structure dynamic behaviour, using modal synthesis, therefore, involves a special development of the sensitivities computation, which takes up 99% of the operating time within an optimization cycle. The sensitivities computation should allow determination of the influence of the substructures design variables on the global behaviour of the assembled structure as well as to have at our disposal a group of sensitivity coefficients directly useful in the case of the global structure optimization.