Keyword: «crack branching»

The regularities, criteria, and mechanisms of crack branching are analyzed. Experimental work has been carried out to study the branching of cracks in brittle polymer and steel, and to measure the crack velocity by breaking conductive strips. A hypothesis of the physical mechanism of crack branching is proposed.

To experimentally determine the rate of crack branching, a series of tensile tests of PMMA samples were carried out at different temperatures, for fracture by internal pressure of thin-walled cylindrical steel shells (vessels) with crack velocity measurement by the method of rupture of conductive strips. A measuring system has been created based on a precision signal converter for resistance thermometers and thermoparks «Tercon» connected to a computer. The crack velocity was measured during rectilinear crack propagation and during crack branching.