Finite element modeling of metal foam structures subject to compressive loading
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Authors
Cooke, Rabon E.
Subjects
Advisors
Kwon, Young W.
Date of Issue
2001-12
Date
Publisher
Monterey, California. Naval Postgraduate School
Language
Abstract
A unit-cell model was developed for open metallic foams in order to predict their effective elastic moduli and the plastic collapse strengths. The model is based on the metallic ligament frame of tetrakaidecahedral shape. The frame structure of the unit-cell was analyzed using the finite element method. The plastic collapse strength was determined when the joints of ligaments became plastic hinges under the assumption of elastic-perfectly plastic material behavior of the metallic material. Both elastic modulus and plastic collapse strength were computed using a single step of finite element analysis without any iterative or incremental procedure. In addition, a very small number of finite elements used. As a result, the unit-cell is computationally very efficient. The next study considered the effective elastic moduli and plastic collapse strengths of the same metallic foams filled with a viscoelastic material. For this study, the unit-cell model was modified. The model considered the ligament frame structure supported by viscoelastic foundation that represented the filler material. In order to validate the unit-cell models, experiments were also conducted. The experimental data agreed very well with the predicted values of both stiffness and strength. Proper design of the materials studied here can have high strength and stiffness, low weight, high damping properties so that they may be useful for multifunctional materials that can be used in the Navy and Department of Defense applications.
Type
Thesis
Description
Series/Report No
Department
Mechanical Engineering
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NPS Report Number
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Format
xiv, 66 p. ;
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This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.