Beam Finite-Element Analysis of Pressurized Fabric Tubes
Publication: Journal of Structural Engineering
Volume 133, Issue 7
Abstract
Lightweight, portable air-pressurized beams and arches serve as primary load-carrying members for a number of civilian and military structures. These members are made from synthetic fibers that are woven or braided into a circular cross section. The pressurized air provides structural capacity by pretensioning the fabric and through its behavior as a confined gas. In this paper, a beam finite element is developed for the analysis of pressurized fabric beams based on virtual work principles. Work done by internal pressure due to deformation-induced volume changes is included in the formulation. A nonlinear moment-curvature relationship accounts for fabric wrinkling, and shear deformations are incorporated. A mixed-interpolation Timoshenko beam element is used to discretize the virtual work expression. A numerical method for determining the moment-curvature relationship of an inflated beam made from a fabric obeying a nonlinear stress–strain relationship is developed. Results of experiments on pressurized fabric beams loaded in three- and four-point bending are presented, and the finite-element model is shown to accurately predict experimentally observed load-deflection response for a range of pressures. Simulations demonstrate that in addition to prestressing the fabric, the pressurized air significantly increases beam capacity as the beam volume decreases due to deformation.
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Acknowledgments
The research reported in this paper was conducted under Contract No. W911QY-05-C-0043 with the U.S. Army Natick Soldier Systems Center. The writers are grateful for this financial support.
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Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 133 • Issue 7 • July 2007
Pages: 990 - 998
Copyright
© 2007 ASCE.
History
Received: Jun 20, 2006
Accepted: Oct 26, 2006
Published online: Jul 1, 2007
Published in print: Jul 2007
Notes
Note. Associate Editor: Keith D. Hjelmstad
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