Experimental K-calibration for corner cracks under bending loading

The geometric correction function F in the expression for stress intensity factors has been determined experimentally by a compliance method for bar-shaped specimens of Al-7475-T761 (with a rectangular cross-section) cyclically loaded in bending at R = -1 and room temperature. The experimental method makes it possible to resolve the behaviour of the crack during the tensile and compressive portions of the loading cycle. This leads to the introduction of the initial notch size as an additional correction parameter. The development of the equilibrium shape of the crack during crack growth up to long surface distances has been investigated. These results have been used for the determination of F. A comparison with literature data is presented.