INVERSE DYNAMIC DESIGN TECHNIQUE FOR MODEL CORRECTION AND OPTIMIZATION

The inverse dynamic design technique presented herein tunes a structur al model to achieve a prespecified frequency response at certain criti cal points of the structure. The technique can correct structural mode ls based on vibration response test data and also can optimize structu ral design. The technique works by partitioning the second-order matri x equations of motion into assigned and auxiliary degrees of freedom a nd then performs a parameter optimization to assign new frequency resp onse data to the model. Design variable linking, symbolic or sparse ma trix solutions, and closed-form gradients are used to streamline the c omputations. The technique still requires a large amount of computatio n, and thus is most applicable to small or moderate size dynamic model s, such as coarse mesh prototype models, or models with repeated geome try or symmetry. Two small order example problems illustrate the techn ique. The first example completely corrects the stiffness matrix of a corrupted analytical model using simulated measured (exact) frequency response data. The second example flattens the first resonance peak of a truss structure by assigning a specified partial frequency response to the model.