Damage detection of SFRC concrete beams subjected to pure torsion by integrating acoustic emission and Weibull damage function

Abstract

In some cases, torsion is the dominant or critical factor contributing to the failure of a concrete member. This research proposes a novel damage detection method for fiber-reinforced concrete beams subjected to pure torsion loading by statistical analysis of acoustic emission (AE) data. Concrete beams with varying water/cement ratios and different fiber volume fractions were subjected to pure torsion during AE monitoring. It was found that the cumulative AE event with respect to the twist angle correlated well to the mechanical loading. A Weibull rupture probability distribution is introduced to quantitatively predict the mechanical damage behavior under pure torsion. A bi-logarithmic regression analysis is carried out to calibrate the Weibull damage distribution function with the detected AE data in order to characterize the torsion fracture process. Moreover, a quantitative approach by means of b-value results is presented in this article to further analyze damage and fracture process. Torsion fracture properties were correlated to the AE parameters, and it was shown that the magnitudes of AE parameters were influenced significantly by mechanical properties of specimens. Therefore, AE would be suitable to describe the fracture of concrete specimens subjected to torsion. Copyright © 2015 John Wiley & Sons, Ltd.