Experimental Study on Changing Natural Frequen-cies of a Free-Free Plate by Changing Environmen-tal Temperature

It is well known that natural frequencies are dependent on material, geometry and boundary conditions. Also, from linear theory it is known that environmental temperature changes can affect material properties such as Young modulus. In this paper, the acoustic and vibration responses due to the variation of natural frequencies in the presence of temperature changes are considered. To perform this study, a rectangular aluminium plate has been freely support-ed within a thermal cycling chamber. The acoustic and vibration responses of an impact exci-tation have been acquired at different temperatures. The results indicate changes in the plate natural frequencies due to temperature variations. The research shows that by increase the temperature, natural frequencies do decrease and the acoustical responses also change ac-cordingly due to the temperature variation.