Shear Correction Factors for Laminated Plates

S HEAR deformations are considered in laminated plate theory in terms of correction factors ktj (or k-j) and modified shear stiffnesses K^ — k^A^ = k-jA^; (ij = 4,5), where AJJ (or A-J) are obtained from assumed constant strain (or stress) fields.1 This work reports the correction factors, obtained by matching cutoff frequencies for propagation of thickness shear waves (ratio of wavelength X to plate thickness H approaching infinity) predicted by plate and elasticity theories. Contents For an exact elasticity solution, the stiffness matrix relating tractions to displacements on the surfaces of each layer is expressed as a function of shear moduli and frequency.2 Cutoff frequencies co/2 for the first two modes dominated by strains yxz and yyz, respectively, are calculated such that determinant of the global stiffness matrix goes to zero. k'n are then evaluated as Kn/A'u, where