A simple accurate method for calculating local stresses around individual fibers in periodic composites

An approximate superposition technique is proposed for calculating the stress fields around individual fibers in composite materials. The method uses the closed form solution for an isolated fiber to construct the local fields. The resulting local fields are validated by comparing with the results from a method based on singular integral equations. The maximum error is 4.3% when the fiber radius to the unit cell length ratio reaches 0.8, with the fiber to matrix modulus ratio up to 20. The associated volume averaged properties can be shown to be approximate upper and lower limits that have the unique feature of depending not only on the fiber volume fraction but also on the fiber packing. (C) 1999 Elsevier Science Ltd. All rights reserved.