Method for selecting axes for prediction of shock response spectrum using transfer function synthesis

Effects of the rotational component on a prediction result of the shock response spectrum given by a transfer function synthesis method are discussed. Shock environment on two structure models, which are a plate model connected by two flat plates and a shock tester model installing a test specimen, is analyzed. The transfer functions of the substructures in these models are initially computed and are synthesized to predict the shock response spectrum in the coupled structure. In the synthesis analysis without the rotational component, the prediction accuracy of the shock response spectrum in the plate model significantly decreases, whereas that in the shock tester model is unaffected. This is attributed to the fact that the shock tester model has high flexible rigidity originated from its structural configuration. This result indicates that the shock response spectrum on the shock tester model can be predicted with sufficient accuracy by only synthesizing the transfer functions with the translation component.