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This study demonstrates the applicability of the similitude theory and scaled models in the prediction of the flutter speed of cross-ply laminated plates subjected to supersonic flow. Such a study is important since it provides the necessary scaling laws and corresponding scale factors, which affect the accuracy of the scale models. In this study, based on structural similitude, the necessary scaling laws are derived using governing equations of the system. These scaling laws are employed to predict the flutter speed of the prototypes by projecting the flutter speed of the model. Both models with complete and partial similarities are discussed. Based on the results of this analytical study, for the special case of the ply level scaling, the complete similarity can be achieved. Furthermore, distorted models with different thicknesses, number of plies, material properties, and mode shapes than those of the prototypes are capable of predicting the flutter speeds of prototypes with good accuracy. The results of this study can be applied to the design of an accurate scale model for flutter analysis of composite plates.

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This article describes the establishment of necessary similarity conditions for geometrically nonlinear vibrations of thin cross‐ply laminated plates. The Von‐karman's strain‐displacement relations have been employed to model structural nonlinearity of the system. The Galerkin procedure is used to reduce the nonlinear partial differential equations to a nonlinearly second‐order ordinary differential equation. An analytical investigation based on the direct use of the governing equations of the systems is undertaken to derive the necessary scaling laws and similarity conditions. In this study, a set of scaling laws are introduced that can predict the nonlinear free vibration frequency of the prototypes by projecting the frequency of the model, accurately. The effects of distorted models with relaxations in the number of plies, stacking sequence, and different vibration amplitudes are studied. The results presented herein indicate that models with different relaxations can predict the nonlinear vibration frequency of prototypes with good accuracy. POLYM. COMPOS., 35:752–758, 2014. © 2013 Society of Plastics Engineers