Using finite element analysis to verify micromechanical models

Conference · Fri Dec 31 04:00:00 EST 1993

OSTI ID:143196

Craddock, J N ^[1]

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1. Southern Illinois Univ., Carbondale (United States). Civil Engineering and Mechanics Dept.

The prediction of mechanical properties of composite materials based on their constituent properties is necessary for the design and analysis of composite material structures. In some high temperature metal matrix composites, calculation of properties such as the transverse modulus is complicated by the formation of a reaction zone between the fiber and the matrix material. The problem of developing micromechanical models to predict this modulus based on constituent properties has been studied Hopkins and Chamis (1) and Craddock and Kocher (2). Some models developed in these previous studies are presented and briefly discussed. One drawback to these models is the lack of corroborating experimental data. Since such experiments are costly, one attractive alternative is to verify the validity of micromechanical models through the use of numerical experiments conducted by using a finite element code. This paper concentrates on the process of using finite element results a means of verifying micromechanical predictions. For this work, a square cell was studied, since this is the principal geometry in the theoretical models considered. A plane stress analysis was conducted using six-noded quadratic triangular elements. Values of stress, strain, and displacement are obtained at locations of interest throughout the cell. Average values of stress and strain are obtained, and an equivalent modulus for the composite is calculated. Differences in the results from the finite element analysis and the theoretical predictions are 5% or less for the cases examined. This agreement suggests that the theoretical models can be used with a great deal of confidence, even without experimental verification. This confidence is obtained easily using the computer and at a great savings in cost and effort. This suggests that the finite element method offers a simple cost efficient way of verify micromechanical models.

• OSTI ID: 143196
• Report Number(s): CONF-930246--; ISBN 0-87339-251-5
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPOSITE MATERIALS
ELASTICITY
MATHEMATICAL MODELS
MECHANICAL PROPERTIES
TUNGSTEN ALLOYS