Modal coupled acoustic-structural frequency-response analysis based on coupled modes

摘要

For most NVH engineers, frequency-response analysis is a commonly accepted tool for noise simulation of coupled acoustic-structural problems. For weakly coupled problems (e.g., air and steel), modal methods are typically used; they are computationally inexpensive and the modal subspace determined by solving two separate eigenproblems on the acoustic and structural domains provides an approximation that is sufficiently accurate to model the coupled problem. But for strongly coupled problems (e.g., water and steel), a much more expensive direct-solution frequency response is usually used. A modal method that uses coupled acoustic-structural modes is available, but it becomes quite expensive if a large number of modes are utilized, which limits applications of such an algorithm to rather low frequency ranges. We propose a new implementation of the frequency-response algorithm based on coupled acoustic-structural modes that drastically reduces analysis time. In addition, parallel implementation is available and demonstrates very good scaling on shared-memory machines. These improvements allow utilizing many more eigenmodes, and thus, extending the area of applications of this method to much higher frequency ranges. The effectiveness of the proposed algorithm is supported by several industrial applications where superior performance (compared to the direct-solution method) and very good accuracy are achieved.