Figure 7.
(a) Full width at half maximum variation (FWHM) (top) and crack-opening strain field (bottom) mapped local to a crack tip in a thick (15 mm) steel sample at Kmin and Kmax(ΔK=28 MPa√m,R=0.05) using a 60×60 μm beam. Much of the broadening local to the crack tip is transient and progresses with the crack tip. (b) The variation in the residual stress parallel to the same crack plane at Kmin across the crack faces for a region of the crack representative of growth at baseline fatigue and across the location of a 100% overload event. All data taken from experiments described in [34] on the energy dispersive beamline ID15 with FWHM expressed as ΔE/Ehkl, where Ehkl is the X-ray energy at which the diffraction peak is centred. (Online version in colour.)