A Possible Use of Bounds on Effective Moduli of Composite Materials

We advocate the use of bounds on the effective moduli of two-phase com posites to deduce possible ranges of microstructural parameters from ex perimental measurements of the effective moduli. In particular we give ex plicit expressions for the bounds on the volume fractions a third-order cor relation parameter. The bounds on the volume fractions are accurate to second-order terms in δx = x 2 — x 1 and δμ = μ 2 — μ 2 , where x 2 and μ 2 (i = 1,2) are the bulk and shear moduli of the phases. When the moduli ratios are of the order 10 or less, the second-order bounds on the volume fractions are tight enough to recommend their use in evaluating end products.