Uniform strain fields and microstructure-independent relations in nonlinear elastic fibrous composites

Uniform strain fields are shown to exist in nonlinear elastic fibrous compo sites and to correspond to curves or surfaces in the macroscopic strain spa ce. Evaluated at each point of such a curve or surface, the effective elast ic tangent or secant moduli are found to be connected by exact relations wh ich are independent of the microstructure at given phase volume fractions. The obtained exact relations include the available ones of linear elastic f ibrous composites as a special case and can serve as benchmarks for analyti cal and numerical approximate schemes elaborated for the prediction of the effective properties of nonlinear elastic fibrous composites. (C) 1999 Else vier Science Ltd. All rights reserved.