Numerical and experimental investigation of flexural performance on pre-stressed concrete structures using electromechanical admittance

This paper presented a numerical and experimental investigation of the performance of flexure-critical pre-stressed concrete (PSC) structures using the electro-mechanical admittance (EMA) of piezoceramic transducers (PZT). In the numerical analysis, three-dimensional finite element modeling was developed for a PSC beam subjected to four-point bending loads. The focus of the numerical analysis was the accurate detection of concrete cracking, and its growth using EMA signatures obtained from a multi-physics harmonic analysis of the electro-mechanical coupled fields. In the experimental study, two PSC beams with different grouting conditions were subjected to four-point bending tests until failure, and were simultaneously monitored by five surface-mounted PZTs. The crack observations, strain measurements, and load-deflection curves were recorded as references for the qualitative and quantitative assessments of the PSC structural flexural performance by the extraction of EMA signature characteristics, root mean square deviation (RMSD) and its rate indices. The experimental results revealed that the proposed method offered a higher sensitivity in comparison with conventional methods. The EMA characteristics could detect concrete cracking and reinforcement yielding in advance; the RMSD rate was more sensitive in the prediction of uploading and failure in the specimens; and the structural performance states such as crack initiation, propagation and penetration, yield and failure were effectively determined using RMSD characteristics. The promising findings in this study provided a potential method for the assessment of flexure-critical PSC structural performances. (C) 2019 Elsevier Ltd. All rights reserved.