Spatial Distribution Characteristic of Transient Vibration Response on Thin Membrane including Wrinkles and Creases induced by Impact Loading

Abstract

   Spatial distribution characteristics of spectra measured at several points on a vibrating membrane surface are investigated. Three membrane models, which are square polyimide films with a flat surface, a wrinkled surface and a creased surface, are treated. An impact load is applied to the corner of the membranes, and a flexural wave propagation as well as a stationary vibration appearing on the membrane surfaces is measured by photogrammetry using a grating projection method. The results show that the vibration characteristics of the membrane surfaces, which are a flexural wave propagation, a natural frequency and a maximum amplitude of the response, are strongly affected by the surface features of the membranes, while the spatial distribution of the logarithmic magnitude of the spectra on the membrane surface has a similar distribution property regardless of the existence of wrinkles and creases.