NUMERICAL ANALYSIS OF VIBRATION AND ACOUSTIC CHARACTERISTICS FOR A CFRP COMPOSITE PLATE

Vibration and acoustic properties of composite materials have been a significant issue to apply to a vehicle due to fuel efficiency and other advantages. To improve NVH of the vehicle consisted of composite material, it is important to exactly analyze characteristics of composite material. The work described in this paper is a study of the dynamic and acoustic response characteristics of a vibrating carbon fiber reinforced plastic (CFRP) rectangular plate. The plates are three depending on the unidirectional fiber orientation angle (0°, 45°, 90°) and excited by a harmonic point force with fixed boundary conditions. First, the natures of vibrating plate, which are eigenfrequencies and mode shapes, are obtained by FEM. Second, numerical simulations for the acoustic results are carried out by weekly coupled FEM/BEM with commercial finite software. Finally, experimental works are also conducted with proto type composite plate to verify numerical results. It is found that the natural frequencies and mode shapes are similar one another and changed according to the fiber orientation angles at lower frequency region. The vibration and sound pressure level are also similar but little different because of the experimental error.