Mechanical Properties of Particulate-Filled Systems

The theory of the elastic moduli of filled systems is reviewed from the interests of the experimental scientist rather than that of the theoretician. From the many theories and equations to be found in the literature, only those which fit closest to what is considered to be the best experimental data are selected for dis cussion. The effects of filler concentration, size, shape, and agglomeration are reviewed as well as the effects of interfacial adhesion. Based largely on experimental experience rather than theory, the general behavior of the stress-strain and dynamic mechanical properties of filled systems are summarized. Theoret ical equations are presented which cover the wide variations found in experimental determinations of thermal coefficients of expansion. To give some perspective to the scientist interested in all types of composite materials, a comparison is made between the modulus of an isotropic composite filled with spherical par ticles and the moduli of anisotropic composite containing uni axially oriented fibers.