TY - GEN
T1 - Finite element verification of the method of neutral axis for damage detection in composite beam structures
AU - Li, Xi
AU - Glisic, Branko
N1 - Funding Information:
The material presented in this paper is supported by the USDOT UTC Program Grant No. DTRT12-G-UTC16 and the National Science Foundation Grant No. CMMI-1362723. The views, findings, recommendations, and conclusions stated or implied in this paper are solely the opinions of the authors. They are not intended to represent the opinions of the funding agencies. The authors would like to acknowledge Dorotea Sigurdardottir, former graduate student in the Department of Civil and Environmental Engineering at Princeton University, for her precious help in initiating the current research. The authors would also like to thank Professor Gucunski's research group at Rutgers University for their collaboration on the testing of the ANDERS slab. Special thanks to Hiba Abdel-Jaber, Kaitlyn Kliewer, and Jack Reilly.
PY - 2016
Y1 - 2016
N2 - The neutral axis in a loaded beam structure is the curve in the cross-section that experiences zero strain. With the absence of axial effects, the healthy location of the neutral axis can be predicted using the position of centroid of stiffness of the beam cross-section. Change in position of the neutral axis can indicate the change in position of centroid, and thus, can be used for damage detection purposes. In this paper, a finite element based analysis was used to verify the method of neutral axis for damage detection in a multi-girder concrete-steel composite test structure with known minute damage. Long-gauge fiber-optic strain and temperature sensors were installed on the test structure at two locations of damage and one healthy baseline location prior to the pouring of the concrete slab. A finite element model was developed and validated using strain measurements for static loading events, and used to predict the healthy neutral axis position at each monitored location. Results show that the finite element prediction of healthy neutral axis location matches very well with actual sensor measurements at the healthy baseline location. An upward shift of the neutral axis is noticed at damaged locations, which was also an observation from previous research. While the change of the position of the neutral axis at damaged locations is confirmation of the damage detection capabilities of the method, further research is needed to explain the physical cause of the detected upward shift of the neutral axis.
AB - The neutral axis in a loaded beam structure is the curve in the cross-section that experiences zero strain. With the absence of axial effects, the healthy location of the neutral axis can be predicted using the position of centroid of stiffness of the beam cross-section. Change in position of the neutral axis can indicate the change in position of centroid, and thus, can be used for damage detection purposes. In this paper, a finite element based analysis was used to verify the method of neutral axis for damage detection in a multi-girder concrete-steel composite test structure with known minute damage. Long-gauge fiber-optic strain and temperature sensors were installed on the test structure at two locations of damage and one healthy baseline location prior to the pouring of the concrete slab. A finite element model was developed and validated using strain measurements for static loading events, and used to predict the healthy neutral axis position at each monitored location. Results show that the finite element prediction of healthy neutral axis location matches very well with actual sensor measurements at the healthy baseline location. An upward shift of the neutral axis is noticed at damaged locations, which was also an observation from previous research. While the change of the position of the neutral axis at damaged locations is confirmation of the damage detection capabilities of the method, further research is needed to explain the physical cause of the detected upward shift of the neutral axis.
KW - Composite beam
KW - Damage detection
KW - Fiber optics
KW - Finite element analysis
KW - Long-gauge strain sensors
KW - Neutral axis
KW - Structural health monitoring
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M3 - Conference contribution
AN - SCOPUS:84994876231
T3 - 8th European Workshop on Structural Health Monitoring, EWSHM 2016
SP - 747
EP - 754
BT - 8th European Workshop on Structural Health Monitoring, EWSHM 2016
PB - NDT.net
T2 - 8th European Workshop on Structural Health Monitoring, EWSHM 2016
Y2 - 5 July 2016 through 8 July 2016
ER -