Nonlocal plasticity effects on fibre debonding in a whisker-reinforced metal

Numerical cell-model analyses for the matrix-fibre debonding in a metal matrix composite are used to study the effect of a characteristic material length in the plasticity description of the matrix material deformations. Characteristic material lengths are already present in the model problem, in the form of fibre sizes and the length associated with the debonding process, so the nonlocal plasticity model brings in an additional material length. The analyses for metal reinforced by aligned short fibres are used to obtain an understanding of the interaction of the different length scales in the problem. The nonlocal plasticity effect tends to increase the stress level at a given overall strain, which clearly tends to promote the onset of debonding.