Structural integrity assessment of pressure equipment by Acoustic Emission and data fractal analysis

Fractal analysis appears to be a relevant tool toward the interpretation of acoustic emissions signals related to the stress and damage of the material and this paper shows how it can be adopted for health monitoring of various structures. The fractal dimension quantifies the order/disorder of the signals and is correlated to the applied stress/pressure and loading cycles. The chart of such evolution allows to evaluate nucleation and propagation of a fatigue crack and to understand the margin of safety of the investigated structure in a specific moment of its life. Fractal analysis of EA signals can be combined with other experimental and theoretical techniques to accurately foresee the damage accumulated and the residual life. In this study we have investigated three pressure tanks at known state of ageing and observed a good agreement with other well-stated methods based on acoustic emissions.