MICROMECHANICS OF COMPOSITE-MATERIALS UNDER COMPRESSIVE LOADING

A common thread joining many engineered materials used dominantly under compressive loading is the presence of a high modulus secondary phase, either fiber or particulate, embedded within a lower modulus matrix phase. To improve their toughness, a frictional or a less-than-coherent interface is strived for in the manufacture of these composite materials. To form a better understanding of the complex behavior of these materials, numerical and experimental models were developed by the U.S. Bureau of Mines that allowed a wide range of micromechanical and fracture behavior to be investigated under compressive loading. Finite element modeling illustrates the effects of interfacial friction and elastic moduli mismatch between the reinforcement and the matrix. Additional results show that packing density or non-dilute concentration of reinforcements have little effect upon the micromechanical behavior under uniaxial compressive loading. These numerical results were then substantiated:by crack initiation experiments on model composite materials.