Experimental observations are essential for the validation for models for crack growth behaviour, particularly in the short crack regime. This paper reports the use of several new methods applied to in-situ short crack observation, including 3D observations of microstructure and cracking by synchrotron tomography techniques, and 2D optical digital image correlation. The examples presented include stress corrosion of stainless steels in aqueous environments, and brittle fracture of of nuclear graphite, where these new methods enable the visualisation of cracks in circumstances in which they would generally be regarded as practically non-observable.
