Dynamic characterization of tapered composite sandwich plate with honeycomb core: Numerical and experimental investigations

Abstract

In the present study, the numerical and experimental investigations on the dynamic performance of tapered composite sandwich plates with various configurations of a honeycomb core material are presented. The tapered composite sandwich plates are considered with the tapered composite plates as face sheets and honeycomb structure with and without strip reinforcements as core materials. Various tapered composite face sheets are formulated by dropping the plies longitudinally at various locations. Further, the various honeycomb core materials are designed such that stiffeners are reinforced at various locations longitudinally and transversely within the honeycomb patterns to enhance the stiffness and damping properties. Higher order Shear Deformation Theory (HSDT) is used to derive the governing differential equations of motion of the various honeycomb tapered composite sandwich plate and solved numerically. Experimental tests are performed to identify the various mechanical properties of composite face sheets and core materials. Various composite sandwich plates are also fabricated to perform the modal analysis and identify the dynamic properties. The effectiveness of the developed numerical model is demonstrated by comparing the natural frequencies and loss factors identified through experimental tests on the prototype sandwich plates. Various parametric studies are also performed to investigate the effect of strip reinforcement in the honey comb patterns, ply drop off and taper angle of face sheets, aspect ratio of sandwich plates, ply orientation of face sheets and boundary conditions on the free vibration characteristics of the tapered composite sandwich plates. In addition, the transverse vibration responses of tapered composite sandwich plates under harmonic force excitation are examined at different types of the honeycomb core design and the performances are compared with those obtained without the addition of composite strips to demonstrate the effectiveness of strip reinforcement in optimizing the stiffness and damping characteristics of the structures.