Determination of Crack Face Displacement by X-ray Tomography and Digital Volume Correlation

Physically small cracks in a ferritic martensitic steel were analyzed in the SPring-8 synchrotron facility. Change in the crack shape under static and cyclic loading could be determined in addition to the crack shape by mounting micro-specimens in an in- beam loading stage. Additional information can be gained by comparing three-dimensional images of the crack faces using volumetric digital image correlation. The displacement field on the crack faces is then available which, in turn, can be correlated to the microstructure determined by serial sectioning and orientation microscopy.