Bending and vibration analysis of composite sandwich plates

A finite element analysis of composite sandwich plates is studied in this paper. The face plates of composite sandwich structures are modeled based on the Mindlin's plate theory. The displacement fields of the sandwich core material are linearly interpolated in terms of the displacements of two face plates. According to this assumption, the transverse shear strains are linearly varied while the transverse normal strain is constant through the core thickness. Finite element analysis based on the Mindlin formulation is adopted using a nine-node isoparametric element. Static and free vibrational problems have been solved to investigate the effect of considering the transverse normal deformation of the core. It was found that when the sandwich plate is subjected to a concentrated load, the aforementioned normal deformation of the core should not be neglected. For the case of free vibration, natural frequencies decrease when the core is considered to be flexible in the transverse normal direction while the natural mode shapes do not have prominent change.