ICSV26

Considering the outstanding engineering properties, such as high strength/stiffness to weight ratios and the capability to be stiff at one location and flexible at another location as desired, internally-thickness-tapered composite plates are used in aerospace, mechanical and green power generation structures. Due to its distinct characteristics such plates require a comprehensive research to understand their dynamic response. In the present paper, the free vibration response of composite plates with staircase internal-thickness-taper configuration is considered considering clamped-free boundary condition. Since closed-form exact solution cannot be obtained for the resulting complex partial differential equation with variable coefficients in space and time coordinates, the Rayleigh-Ritz method in conjunction with the Classical Laminated Plate Theory (CLPT) is used to obtain the system mass and stiffness matrices for out-of-plane bending vibration. In this approach, the stress and strain distributions in the laminated plate are determined in terms of mid-plane displacements and rotations corresponding to CLPT and as functions of taper angle and fiber orientation angle, and using these the kinetic and strain energies of the plate are calculated. Following the variational approach of the Rayleigh-Ritz method, the eigen problem for the free vibration response is obtained, and the natural frequencies and mode shapes of the plate are determined by solving this eigen problem. Numerical and symbolic computations have been performed using the software MATLAB. The influences of taper angle under thickness constraint and length constraint on the natural frequencies of the laminated composite plate are investigated for different stacking sequences of the laminate. Important design aspects are systematically brought out.