Axisymmetric Free Vibration of Thick Orthotropic Hemispherical Shells Under Various Edge Conditions

Abstract

Axisymmetric free vibration of moderately thick polar orthotropic hemispherical shells are studied under the various boundary conditions with sliding, guided pin, clamped, and hinged edges. Based on the improved linear elastic shell theory with the transverse shear strain and rotatory inertia taken into account, the dynamic equlibrium equations are formulated and transformed into the displacement form in terms of mid-surface meridian and radial displacements and parallel circle cross-section rotation. These partial differential equations are solved by the Galerkin method using proper Legendre polynomials as admissible displacement functions with the aid of the orthogonality and a number of special integral relations. Natural frequencies and modes found from the eigenproblems are shown with reasonable results.