In-situ fracture tests were carried out on the I12 beamline at the Diamond Light Source. Four Al-Ti metal-matrix composites (MMCs), with two crack lengths, were studied to assess for the impact of in-plane constraint. Synchrotron X-ray computed tomography and synchrotron X-ray diffraction were used to measure total strain and elastic strain respectively. In this work, the measured elastic strains in the samples are detailed as a function of applied load and compared against those predicted from a 3D elastic-plastic finite element model. The modelled strains increased asymptotically towards the tip of the electro discharge machined notch. The experimental results do not highlight the same response, which is due to a combination of blunting and low experimental spatial resolution. Far field experimental and measured strain fields converged, notably in the test piece containing a long notch (a/W = 0.5) and higher levels of constraint.
- Plastic constraint
- Strain energy release rate