Vibration response models of a stiffened aluminum plate excited by a shaker

Vibration response predictions from commercially available vibroacoustic computer codes were compared with experimentally measured velocities of a stiffened aluminum plate excited by a shaker. Predictions were computed using two energy finite element codes, a statistical energy analysis code, and a structural finite element code. The stiffened aluminum plate was approximately 1.44 m², with three Z-section stiffeners and six inverted-hat stiffeners riveted to the plate. Shaker excitation cases discussed here include normal excitation of a subpanel and normal excitation of a stiffener. Comparisons were done for the spatially averaged mean square velocity over the entire panel and mean square velocity variation spatially averaged within each of eight central subpanels. Within the finite element analysis, the accuracy of simple beam elements was compared with a more complex beam representation consisting of plate elements. In the SEA model, a ribbed-panel single subsystem model was compared with a multiple-subsystem plate-beam model. Different methods for representing the power input for the stiffener-excitation case are discussed.