VIBRAÇÕES E ESTABILIDADE DE CASCAS CILÍNDRICAS SANDUÍCHE COM NÚCLEO DE ESPUMA METÁLICA COM GRADAÇÃO FUNCIONAL

Resumo

Cylindrical shells have applications in several areas of engineering. The last decades have
seen the emergence of several new materials and production techniques to be used in these structural
elements. Functionally graded materials, metal foams and sandwich structures are part of this
development. The sandwich shells, with solid metal faces and metal foam core, are used to improve
structural performance in line with a reduction in weight. The objective of this work is to study the
natural frequencies and the critical loads of sandwich shells with a metal foam core (CSCN) and
compare the results with those of a homogeneous isotropic shell (CH) and with functionally graded
(CGF) shells. For this, the Donnell shell theory is used. First, the equations of motion are derived and
using the analytical solution for a simply supported shell, the mass, stiffness and geometric matrices
are obtained, allowing the calculation of natural frequencies and critical loads under axial compression
and lateral pressure. In order to evaluate the importance of the foam core, shells of the same mass and
shells with the same natural frequencies and critical loads are analyze.