On the Point Method and the Line Method notch effect predictions in Al7075-T651

The Point Method and the Line Method are two approaches derived from the Theory of Critical Distances, used in conjunction with a characteristic material length parameter when performing fracture assessments on any kind of stress risers, including notches. This paper analyses the application of both the Point Method and the Line Method for the prediction of the notch effect on the aluminium alloy Al7075 in T651 conditions. The parameters involved in the analysis are calibrated through a combination of experimental tests and finite elements modelling, and a comparison is made between the experimental results and the predictions provided by these two approaches. Also, a Scanning Electron Microscopy analysis is performed, establishing relations between the fracture mechanisms and the predictions provided by the Theory of Critical Distances. The results obtained demonstrate the suitability of the Point Method and the Line Method for the analysis of notches.

► The application of both the PM and the LM on aluminium alloy Al7075-T651 has been validated. ► Only at high notch radii have the predictions provided significant deviations from the experimental results. ► Some precautions should be considered when performing the calibration of the TCD parameters. ► The evolution of the apparent fracture toughness is caused by the evolution of the fracture micromechanisms.