EFFECT OF INCLUSION SHAPE AND VOLUME FRACTION ON THE DENSIFICATION OF PARTICULATE COMPOSITES

The densification around rigid inclusions of linear visco-plastic porous matrices is studied. The role of particle shape (aspect ratio, presence of sharp corners, number of sides, clustering) and of matrix compressibility (i.e. Poisson's ratio) is investigated in plane strain using the conformal mapping method. It is shown that a high aspect ratio, a low Poisson's ratio or clusters of particles generate large densification gradients around the inclusions. The role of the particle volume fraction on densification and shear deformation is then studied using an upper bound method. Strengthening during densification is obtained for low Poisson's ratios and high aspect ratios; high Poisson's ratio and high aspect ratios result in high strengthening during shear.