To predict the dynamic response and acoustic radiation from an underwater structure, large impedance method is provided based on finite elemnt/ boundary element method, which uses the vibration data got from experiment as input. To use large impedance method, an imaginary element with large impedance should be loaded at the test point. A force should be driven on the test point, which leads to the same vibration response at the test point as is tested. The imaginary element may be large mass or large grounded spring, which is chosen according to the item tested at the test point. Since the dynamic response is effected only by the response of the test point, the impedance of the main structure and the transfer impedance from the test point to the main structure, the driven equiment which is on the upstream of the test point needn’t be built in the finite element model, which leads to great convinience in prediciton of dynamic response and acoustic radiation from an underwater structure. Dynamic response and acoustic radiation from a steel cylindrical model is predicted using large impedance method. Comparisons of numerical results and experimental results show good agreement. Large impedance method is validated as useful for predicting dynamic response and acoustic radiation from an underwater structure using the vibration data got from expeiment as exciting input.
Ji Gang;Zhou Qi-dou;Xie Jian-bo.
Prediction of dynamic response and acoustic radiation from an underwater structure based on the vibration data got from experiment[J]. Journal of Vibration and Shock, 2011, 30(11): 135-141,
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