Three-dimensional fractographic analysis of total fracture areas in 6082 aluminium alloy specimens under fatigue bending with controlled damage degree

Non-destructive methods are powerful tools in modern industry to assess the structural integrity of engineering critical parts subjected to fatigue loading. This paper proposes a mixed mechanical-metrological approach able to account for the three-dimensional fractographic damage in samples subjected to fatigue bending loading histories based on the system dynamics. The system records the changes in the dynamic response, using uniaxial acceleration sensors, enabling the correlation of the stiffness variations with the crack length and the residual loading capacity. Fracture topologies are analysed via standard surface texture parameters, namely height, material volume and void volume parameters, for different degrees of fatigue damage. The results show a clear relationship between the changes in the recorded accelerations, which are associated with the degree of fatigue damage, and the values of the above-mentioned surface texture parameters.