buckling and Vibration analysis of a thick cylindrical sandwich panel with flexible core using an improved high-order theory

In this paper, the behavior of free vibrations and buckling of the thick cylindrical sandwich panel with a flexible core and simply supported boundary conditions using a new improved ýhigh-order sandwich panel theory were investigated. An axial compressive load is applied on the edges of the top and bottom face sheets simultaneously. The formulation used the third-order polynomial description for the displacement fields of thick composite face sheets and for the displacement fields in the core layer based on the displacement field of Frostig's second model. In this model, there are twenty seven degree of freedom. The transverse normal stress in the face sheets and the in-plane stresses in the core were considered .For calculated exact solution, according to thick face sheets, all of the stress components were engaged. The equations of motion and boundary conditions were derived via the Hamilton principle. Moreover, the effect of some important parameters such as those of thickness ratio of the core to panel, the length to radius ratio of the core, cumferential wave number and composite lay-up sequences on free vibration response and buckling of the panel were investigated. In order to validate the results, the obtained results were compared with those obtained using finite element ABAQUS software. The advantage of this paper is simplicity, considering face sheets as thick, exact solution and the considering of important terms such as (1_c/R_c ) in equations.