In order to evaluate the mode II sliding failure in poly(methyl methacrylate) (PMMA), various types of specimens have been tested. Without side grooves in the specimens, the polymer fails when macroscopically sheared generally by an off-plane crack with the crack opening behaviour of mode I. With side grooves along the shear plane, the matrix shear strength dominates failure, and real mode II sliding failure was not attainable. In uniaxially reinforced composites, shear failure is enforced in the matrix by the fibres, which prevent the matrix from opening in an off-plane direction.
Посилання на статтю:
An approach towards understanding mode II failure of poly (methyl methacrylate) / F. Ramsteiner // Polymer. – 1993. – Vol 34. – P. 312-317.