Probabilistic dynamic analysis with ADINA

In structural analysis the extreme values of the structural response quantities are of primary interest. In the case of linear structures under stationary Gaussian random exicitations a probabilistic analysis provides the expected extreme values as well as confidence intervals in a mathematically rigorous way. The analysis becomes particularly simple in modal coordinates, if the damping matrix decouples. All quantities required for the probabilistic analysis are then readily obtained from the modal covariance matrices. The evaluation of these matrices by analytical integration is discussed. This method is computationally very effective and maintains full accuracy in the dynamic properties of the structural model. The implementation of the probabilistic analysis in ADINA is outlined. As an illustration, the seismic analysis of a structure under multiple support random excitation is presented.