Measuring stress intensity factors with a camera: Integrated digital image correlation (I-DIC)

A novel 'integrated' approach coupling image correlation and elastic displacement field identification provides a powerful and accurate tool to evaluate mode I and II stress intensity factors. This technique is applied to silicon carbide subjected to a sandwiched three-point bend test, using digital pictures obtained in optical microscopy where the pixel physical scale is about 2 mu m. A crack whose maximum opening is 500 nm can be detected and its geometry identified. The toughness is determined well within a 10% uncertainty.