A new modal synthesis program: OSCAR

Among CASTEM 2000 tools, OSCAR is devoted to dynamic analysis through modal synthesis. Typically, for performing dynamical analysis, for instance, vibration or seismic calculation, it is usually possible to retain the modes in the low frequency range. Also, the main advantage of modal synthesis is the drastic reduction of degrees of freedom. Modal analysis can be used when the sub-structures remain elastic and have only small displacements. This is a satisfactory assessment for most vibration calculations. More over, modal analysis can deal with problems involving localized nonlinearities. In such a case, substructure vibration modes are calculated apart from nonlinear phenomena. Then structural motion is projected on the modes which are coupled by describing the non-linear behaviour links. Relatively inexpensive, numerical simulations in non-linear dynamics can be performed with OSCAR either to analyse the behaviour of real systems or to validate simplified models, such as linear equivalent ones. It is an efficient way of investigating the influence of non-linear links on global vibratory behaviour of structures. (orig.)