Crack path kinking under generalized stress state

Results of experimental investigations of three-point asymmetric bending applied to beams made of materials with substantially different structural, strength, and strain characteristics are presented. The effect of different types of fracture on the formation of crack kinks under a generalized stress state is revealed. Strength curves of the Coulomb-Mohr type are obtained for Plexiglas and fine-grained concrete, which are characterized by the quasi-brittle and brittle types of fracture, respectively. Dependences of the kink angles of the crack paths on the stress state in the case of three-point bending are described for these materials. __________ Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 50, No. 3, pp. 205–213, May–June, 2009.