SEARCH

SEARCH BY CITATION

Abstract— When an initially-parallel-sided tab of material, cut into an isotropic finite-width sheet, is torn by pulling the outer tabs in one direction, and the center in the opposite, the cracks may follow a parallel path, diverge outwards, or converge inwards depending on the widths of the inner and outer “legs”. At the same time, the untorn portion of the material may rotate relative to the pulling axis. The phenomenon is observed in globally elastic tearing, elastoplastic tearing, and in rigid-plastic tearing. A fracture mechanics model using minimum energy explains the tear paths and rotations. Experiments on NS4 aluminium alloy confirm the analysis. The relationship of leg widths and bend radii with standard trousers tear testing of ductile materials is explained.