High-rank nonlinear sequentially laminated composites and their possible tendency towards isotropic behavior

This work is concerned with the determination of the effective behavior of sequentially laminated composites with nonlinear behavior of the constituting phases. An exact expression for the effective stress energy potential of two-dimensional and incompressible composites is introduced. This allows to determine the stress energy potential of a rank-N sequentially laminated composite with arbitrary volume fractions and lamination directions of the core laminates in terms of an N-dimensional optimization problem. Stress energy potentials for sequentially laminated composites with pure power-law behavior of the phases are determined. It is demonstrated that as the rank of the lamination becomes large the behaviors of certain families of sequentially laminated composite tend to be isotropic. Particulate composites with both, stiffer and softer inclusions are considered. The behaviors of these almost isotropic composites are, respectively, softer and stiffer than the corresponding second-order estimates recently introduced by Ponte Castaneda (1996). (C) 2002 Elsevier Science Ltd. All rights reserved.