Effect of size and configuration of 3-point bend bar specimens on J– R curves

Abstract

Elastic–plastic fracture toughness of J Q values, crack opening displacement (COD) values for crack initiation and J resistance ( J– R) curves for crack extension of a 7075-T6 aluminum alloy were measured with 3-point bend bar specimens of different sizes. Width and the thickness of the specimens ranged from 1.25 to 20 mm. The a/ W also ranged from 0.125 to 0.5. J Q and COD values exhibited no appreciable change with specimen size and configuration, while the J range and crack extension increased with ligament size.