Deterministic and probabilistic fatigue prognosis of cracked specimens using acoustic emissions

This paper presents and compares two methodologies for predicting fatigue life of structural elements using Acoustic Emission data. These methodologies have the potential to be used by bridge owners to assess the state of key structural elements in an almost real time fashion and forecast the state of the element at any time in the future. This information can be used to schedule maintenance or replacement. The proposed methodologies have the potential to be applied to any structural element with active cracks and do not require knowledge of the load history. One approach uses fracture mechanics models and relationships between acoustic emission features, while the other approach is based on relationships between acoustic emission features and stress intensity range to estimate the stress intensity range of a particular crack a number of cycles in the future. Compact tension specimens are used to explore the capabilities of both techniques.

► Two Techniques for fatigue life prognosis that use AE are presented and compared.
► Methodologies do not require load history neither S-N curves.
► Deterministic technique allows assertive fatigue prognosis at low computational cost.
► Probabilistic technique uses only acoustic emission and strain gauge measurements.
► Methodologies performance were compared using data from a compact tension specimen.