Debonding of particles in anisotropic materials

Effects of geometrical anisotropy as well as plastic anisotropy are studied in relation to debonding of rigid inclusions embedded in a metal. Full finite strain analyses are carried out for a cell model under plane strain conditions, and the average overall stress–strain response of the cell is calculated. For increased triaxiality the onset of matrix–particle debonding occurs at a significantly reduced overall strain of the cell. The point of initial debonding is nearly unaffected by variations of the shape of the inclusions, but complete debonding occurs earlier if the inclusions are elongated perpendicular to the main tensile direction. The same effect is observed, if the spacing of the inclusions is larger in the main tensile direction than in the transverse direction. For the orientations of plastic anisotropy considered, the debonding initiates and grows at a much lower overall strain than if the material was plastically isotropic. It is found for mixed geometrical and plastic anisotropy, that plastic anisotropy promotes debonding initiation, whereas the occurrence of complete matrix–particle debonding is quite sensitive to the type of geometrical anisotropy.