2ND-ORDER EFFECTS IN THE CRITERIA FOR THE START OF CRACKS IN IDEALLY BRITTLE HYPERELASTIC ELASTOMERS

The formulation and solution of a plane problem in the theory of elast icity for a hyperelastic medium containing a crack are given. Expressi ons are obtained for the energy integral in order to investigate the c onditions for the start of a crack. Special cases in the form of cleav age and transverse shear cracks are considered. Second-order effects d o not show up in the case of cleavage cracks, but in the case of trans verse shear cracks they show up in the form of a deviation of the crac k from the initial direction, which agrees with observations. (C) 1997 Elsevier Science Ltd.