Date of Award

9-1991

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Department of Aeronautics and Astronautics

First Advisor

Anthony N. Palazotto, PhD

Abstract

Eight variations of higher-order transverse shear deformation (HTSD) theory were developed for composite shells. Three attributes were varied to produce the eight variations. These attributes include the order of the thickness expansions used to approximate the shell shape factors and the assumed linear displacement field and the nonlinearity of transverse shear strain. Several cylindrical shell problems were investigated using SHELL, a finite- element code with a 36 degree of freedom cylindrical shell element. MACSYMA, a symbolic manipulation code, was used to formulate the element independent stiffness arrays for each variation of the theory. When all nonlinear strain- displacement terms for transverse shear were included for thin shallow isotropic cylindrical shells, the theory predicted a more flexible response during collapse. Higher-order thickness expansions had negligible effect upon results for shallow shell problems investigated. For deeper shells, the linear displacement assumption prohibited the use of nonlinear strain-displacement relations for transverse shear strains. Thus, for deep shells nonlinearity was limited to in-plane strain-displacement relations.

AFIT Designator

AFIT-DS-ENY-91-1

DTIC Accession Number

ADA242017

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