Techno Press
You logged in as Techno Press

Earthquakes and Structures
  Volume 19, Number 1, July 2020 , pages 29-44
DOI: https://doi.org/10.12989/eas.2020.19.1.029
 


Structural health monitoring of seismically vulnerable RC frames under lateral cyclic loading
Constantin E. Chalioris, Maristella E. Voutetaki and Angelos A. Liolios

 
Abstract
    The effectiveness and the sensitivity of a Wireless impedance/Admittance Monitoring System (WiAMS) for the prompt damage diagnosis of two single-storey single-span Reinforced Concrete (RC) frames under cyclic loading is experimentally investigated. The geometrical and the reinforcement characteristics of the RC structural members of the frames represent typical old RC frame structure without consideration of seismic design criteria. The columns of the frames are vulnerable to shear failure under lateral load due to their low height-to-depth ratio and insufficient transverse reinforcement. The proposed Structural Health Monitoring (SHM) system comprises of specially manufactured autonomous portable devices that acquire the in-situ voltage frequency responses of a network of twenty piezoelectric transducers mounted to the RC frames. Measurements of external and internal small-sized piezoelectric patches are utilized for damage localization and assessment at various and increased damage levels as the magnitude of the imposed lateral cycle deformations increases. A bare RC frame and a strengthened one using a pair of steel crossed tension-ties (X-bracing) have been tested in order to check the sensitivity of the developed WiAMS in different structural conditions since crack propagation, damage locations and failure mode of the examined frames vary. Indeed, the imposed loading caused brittle shear failure to the column of the bare frame and the formation of plastic hinges at the beam ends of the X-braced frame. Test results highlighted the ability of the proposed SHM to identify incipient damages due to concrete cracking and steel yielding since promising early indication of the forthcoming critical failures before any visible sign has been obtained.
 
Key Words
    reinforced concrete (RC) frame; structural health monitoring (SHM); lateral cyclic testing; seismic vulnerability; shear; piezoelectric lead zirconate titanate (PZT); damage assessment
 
Address
Constantin E. Chalioris and Angelos A. Liolios:Department of Civil Engineering, School of Engineering, Democritus University of Thrace, Xanthi 67100, Greece
Maristella E. Voutetaki: Department of Architectural Engineering, School of Engineering, Democritus University of Thrace, Xanthi 67100, Greece
 

Techno-Press: Publishers of international journals and conference proceedings.       Copyright © 2024 Techno Press
P.O. Box 33, Yuseong, Daejeon 305-600 Korea, Tel: +82-42-828-7996, Fax : +82-42-828-7997, Email: admin@techno-press.com