Damage evaluation and failure mechanism analysis of steel tube confined reinforced-concrete columns by acoustic emission technology

Abstract

As a new kind of composite structures and its advantages, the using of steel tube confined reinforced concrete (STCRC) columns have received increasing attention in civil engineering. Acoustic emission (AE) technique is applied to monitor the damage process of STCRC columns during an uniaxial compression test. The aim of this study is to investigate the damage evaluation and failure mechanisms of the STCRC columns from the perspective of microscopic damage. Typical AE parameters are extracted to quantify different damage condition and identify the critical point. Peak-frequency analysis classify the damage signal into groups, representing different AE generation mechanisms. Extended AE features, such as the RA value and the average frequency are calculated to discriminate the cracking modes of core concrete. The probability based Gaussian mixture model (GMM) are proposed for unsupervised damage pattern recognition. All presented AE results are good in accordance with the observed experimental outcomes. The AE technology enabled evaluating the damage condition, identifying critical point, disclosing the failure mechanism, and classifying damage modes for steel confined RC columns effectively.