Evaluation of the Pumping Action of a Barrel-Shaped Composite Shell Structure

Abstract

This paper evaluates the pumping-action potential of a flexible-matrix-composite barrel-shaped shell-of-revolution structure. The pumping-action potential is defined by the relative radial reduction due to a specific applied axial stretching. The fundamental concept of the investigated pumping action is based on the phenomenon that angle-ply fibrous flexible-matrix-composites, with fiber angle orientation of [±θf], can exhibit unprecedented high values of the in-plane Poisson’s ratio. Consequently, upon stretching an angle-ply flexible-matrix-composite axisymmetric shell-of-revolution structure, a substantial reduction in its diameter can be realized and a potential pumping action is provided. In the current paper, the effect of the large deformation on the pumping action of a barrel-shaped (concaved-out) shell-of-revolution composite structure is evaluated. A mathematical model governing the large deformation of an axisymmetric barrel-shaped shell-of-revolution flexible-matrix-composite structure is presented and the response due to axial stretching, for different barrel curvature (maximum diameter), is found using the B-spline collocation numerical technique. In addition, a limited, preliminary experimental work is presented. A carbon/polyurethane barrel-shaped shell-of-revolution structure is constructed, and tested using the Tinius-Olsen testing machine. The crude preliminary results are compared with the corresponding analytical ones, and a discussion of the analytical/experimental results and their implications are addressed. The investigation demonstrates that a barrel-shaped angle-ply flexible-matrix-composite shell structure possesses a relatively high pumping potential.