A dual-imaging framework for multi-scale measurements of fatigue crack evolution in metallic materials

This paper presents a dual-imaging methodology to investigate fatigue crack initiation & propagation along the lateral and transverse directions in Al7075 flat specimens having a one-sided V-notch. The framework consists of a confocal and a digital microscope. The confocal microscope can detect the short crack initiation at a length-scale of 3 µm while the digital microscope has the capability of reliably measuring cracks at a scale of 0.5 mm....