Correction and Extension of van der Poel's Method for Calculating the Shear Modulus of a Particulate Composite.

Van der Poel's method (Rheol. Acta 1, 198 (1958)) for calculating the shear modulus of a particulate composite agrees well with experimental data, but its validity has been questioned, and it was applicable only to composites in which the matrix material is incompressible. These limitations are removed in this paper in which an error in the original derivation is corrected, and the method generalized to apply to any matrix material. Calculations using the corrected theory show that despite the error, a table of shear modulus values published with the original theory is sufficiently correct for most practical purposes. Applicability of the generalized method to the large class of composites having compressible matrices is discussed. Shear moduli calculated by the corrected and extended method are compared with corresponding values calculated by other methods currently used.