Modelling the Vibrations of Convex Polygonal Plates by the Image Source Method

The aim of this study is to investigate the capability of the image source method (ISM) for predicting medium and high frequency flexural vibrations of damped convex polygonal thin plates including various boundary conditions. Besides its classical use in room acoustics, ISM has already been applied to polygonal plates comprising simply supported and roller supported edges. Such boundaries include reflection coefficients that are independent from the angle of incidence of waves. In order to render ISM applicable to more complex boundary conditions, the existing formulation must be adapted. In this paper we present a new formulation of ISM which allows to include angle-dependent reflection coefficients. For practical implementation, an approximation consisting in neglecting edge effects is investigated. An example of implementation is presented and the interest of the method for high frequency vibration modelling is discussed.