title: A novel multi-segment path analysis based on a heterogeneous velocity model for the localization of acoustic emission sources in complex propagation media.
abstract: In acoustic emission analysis, common source location algorithms assume, independently of the nature of the propagation medium, a straight (shortest) wave path between the source and the sensors. For heterogeneous media such as concrete, the wave travels in complex paths due to the interaction with the dissimilar material contents and with the possible geometrical and material irregularities present in these media. For instance, cracks and large air voids present in concrete influence significantly the way the wave travels, by causing wave path deviations. Neglecting these deviations by assuming straight paths can introduce significant errors to the source location results. In this paper, a novel source localization method called FastWay is proposed. It accounts, contrary to most available shortest path-based methods, for the different effects of material discontinuities (cracks and voids). FastWay, based on a heterogeneous velocity model, uses the fastest rather than the shortest travel paths between the source and each sensor. The method was evaluated both numerically and experimentally and the results from both evaluation tests show that, in general, FastWay was able to locate sources of acoustic emissions more accurately and reliably than the traditional source localization methods.
authors.affiliation: Institute of Structural Engineering, ETH Zurich, Stefano-Franscini-Platz 5, 8093 Zurich, Switzerland. Electronic address: gollob@ibk.baug.ethz.ch.
authors.forename: Stephan
authors.initials: S
authors.lastname: Gollob
authors.affiliation: Institute of Applied Mechanics, University of Stuttgart, Pfaffenwaldring 7, 70569 Stuttgart, Germany. Electronic address: georg.kocur@mechbau.uni-stuttgart.de.
authors.forename: Georg Karl
authors.initials: GK
authors.lastname: Kocur
authors.affiliation: Civil & Environmental Engineering, Portland State University, Engineering Building, Portland, OR 97201, USA. Electronic address: thomas.schumacher@pdx.edu.
authors.forename: Thomas
authors.initials: T
authors.lastname: Schumacher
authors.affiliation: Civil & Environmental Engineering, Portland State University, Engineering Building, Portland, OR 97201, USA. Electronic address: lamhamdi@pdx.edu.
authors.forename: Lassaad
authors.initials: L
authors.lastname: Mhamdi
authors.affiliation: Institute of Structural Engineering, ETH Zurich, Stefano-Franscini-Platz 5, 8093 Zurich, Switzerland. Electronic address: vogel@ibk.baug.ethz.ch.
authors.forename: Thomas
authors.initials: T
authors.lastname: Vogel
keywords: Acoustic emission; Heterogeneous velocity model; Multi-segment wave propagation path; Numerical model; Reinforced concrete; Source location