AN INVESTIGATION OF 2-DIMENSIONAL AND 3-DIMENSIONAL MODELS FOR PREDICTING THE ELASTIC PROPERTIES OF PARTICULATE-REINFORCED AND WHISKER-REINFORCED COMPOSITE-MATERIALS

A boundary element method is coupled with a variety of two-dimensional and three-dimensional "repeat cell" models to analyse particulate- and whisker-reinforced composite materials. The elastic properties are predicted for volume fractions ranging up to 50%. The commonly employed axisymmetric repeat cell approximation is shown to provide an accurate representation of the full three-dimensional solution if the volume fraction is in general less than approximately 20%, although the range may be larger in certain circumstances. A comparison of aligned and staggered reinforcement models for the case of SiC-strengthened aluminium alloy indicates that reinforcement alignment is not important provided that the flexibility of the reinforcement is taken into account. If the reinforcement is regarded as rigid, then the alignment is important at volume fractions in excess of approximately 20% for the case of spherical reinforcement or 10% for the case of whisker reinforcement.