Effective elastic and failure properties of fiber aligned composites

Abstract

A digital image processing technique is used for measurement of centroid coordinates of fibers with forthcoming estimation of statistical parameters and functions describing the stochastic structure of laminated fiber composites. Comparative statistical analysis of the experimentally measured and numerically simulated fiber distributions are performed. We consider a linearly elastic composite medium, which consists of a homogeneous matrix containing a statistically homogeneous set of ellipsoidal inclusions. The multiparticle effective field method (MEFM) [Appl. Mech. Rev. 54 (2001) 1] based on the theory of functions of random variables and Green's functions is used to demonstrate the dependence of effective elastic moduli of fiber reinforced composites on the fiber radial distribution functions as estimated from measured experimental data as well as from the ensembles generated by the proposed method. The MEFM is applied for the estimations of second statistical moments of stresses in both the constituents and the interfaces between the matrix and fibers. These estimations are used in turn for the prediction of the effective envelope for failure initiation. The dependence of the effective failure envelope on the elastic, geometrical, and failure parameters of the constituents and the interphase matrix/fibers are analyzed.