Damage‐sensitive impedance sensor placement on multi‐strand anchorage based on local stress variation analysis. Issue 7 (7th March 2020)

• Record Type: Journal Article
• Authors: Dang, Ngoc‐Loi; Huynh, Thanh‐Canh; Pham, Quang‐Quang; Lee, So‐Young; Kim, Jeong‐Tae
• Is Part Of: Structural control and health monitoring. Volume 27:Issue 7(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-03-07
• Subjects: electromechanical impedance -- multi‐strand anchorage -- prestress force -- sensor placement -- strand breakage detection -- stress analysis; Structural engineering -- Periodicals; Structural control (Engineering) -- Periodicals; Automatic data collection systems -- Periodicals; Detectors -- Periodicals; 624.17
• DOI: 10.1002/stc.2547
• Languages: English
• ISSNs: 1545-2255

Abstract

Summary: An important issue in impedance‐based damage monitoring is to deploy sensors in proper positions in which damage‐sensitive impedance responses can be captured effectively. In this study, a full‐scale multi‐strand anchorage is analyzed to determine optimal locations of piezoelectric sensors for impedance‐based monitoring of locally damaged strands. First, stress variations of the multi‐strand anchorage are experimentally measured to estimate the anchorage behavior under the effect of locally damaged strands. Strain signals are examined for axial, circumferential, and radial stress components under the variation of prestress forces. Second, a finite element analysis is made on the multi‐strand anchorage to back up the experimental findings. Third, a damage‐sensitive structural model is interpreted for the local strand breakage. Finally, impedance responses sensitive to local strand breakage are experimentally examined for a few scenarios simulated in the anchorage system. PZT (lead zirconate titanate) sensors deployed on the anchor head and the bearing plate are evaluated to comparatively determine ideal regions of interest for impedance monitoring. The results show that the greater stress variation yields the greater variations in impedance responses and the near‐top and near‐anchor heads are ideal regions of interest for damage‐sensitive impedance monitoring.