FIBER BRAGG GRATING SENSOR APPLICATIONS FOR STRUCTURAL HEALTH MONITORING

2017-09-30
Karataş, Cansu
Değerliyurt, Boray
Yaman, Yavuz
Şahin, Melin
A well-known structural health monitoring method used to detect and locate damage in civil engineering structures is vibration-based damage identification. It typically monitors the civil structure over time to spot slow or sudden changes in its natural frequencies, damping factors or modal displacements. This approach can prove very powerful, but the sensitivity of those properties to local damage can be rather low. In addition, their cross-sensitivity to environmental influences may completely mask the effect of damage, even of severe damage. Instead one can consider the modal strains and curvatures, which are much more sensitive to local damage, but direct (quasi-)distributed monitoring of these quantities with sufficient strain resolution as well as adequate spatial resolution is not straightforward with current measurement techniques. This stems from the small (sub-microstrain) amplitudes of the strain levels occurring following ambient or operational excitation of the structure under test. To deal with this issue we propose and demonstrate a novel mechanical transducer that amplifies the strain applied to an optical fiber Bragg grating sensor with a factor of about 36. In addition the transducer resonance frequencies are sufficiently high to ensure accurate dynamic strain monitoring of civil structures under ambient excitation.

Suggestions

Structural Health Monitoring system of composite beams with surface bonded and embedded Fibre Bragg Grating sensors
Deǧerliyurt, Boray; Karataş, Cansu; Şahin, Melin; Yaman, Yavuz (2017-01-15)
Fibre Bragg Grating (FBG) sensors are frequently being used for Structural Health Monitoring (SHM) of aerospace structures. One of the most important advantages of using FBG sensors is that it is possible to embed them into composites. In this paper, manufacturing methods of composite specimens with embedded FBG sensors are given. To avoid stress concentrations at ingress/egress regions of fibre optic wires, PTFE (Teflon) tubes were used during manufacturing. Moreover, FBG connectors melt at high curing tem...
Vulnerability assessment of reinforced concrete moment resisting frame buildings
Erduran, Emrah; Yakut, Ahmet (2007-04-01)
A detailed seismic performance assessment procedure has been developed for reinforced concrete (RC) frame buildings with masonry infill walls. The procedure is based on member damage functions, in terms of interstory drift ratios. These functions are developed for the primary components, namely, columns, beams, and infill walls. For developing these functions, analytical investigations to determine the influence of several parameters on the damageability of components were combined with experimental data. A...
Finite element analysis and tests of composite beams with fiber bragg grating sensors under torsional load for structural health monitoring applications
Karataş, Cansu; Yaman, Yavuz; Department of Aerospace Engineering (2017)
In this thesis, feasibility of Fiber Bragg Grating sensors for Structural Health Monitoring applications of composite structures is studied. The method and essentials for the manufacturing process of composite beams with embedded Fiber Bragg Grating sensors are presented. Composite beams instrumented with surface bonded and embedded Fiber Bragg Grating sensors are tested under static torsional load. In addition, Finite Element Analyses of composite beams under torsional load is conducted using the commercia...
Component based seismic vulnerability assessment procedure for rc buildings
Erduran, Emrah; Yakut, Ahmet; Department of Civil Engineering (2005)
A detailed seismic performance assessment procedure has been developed for reinforced concrete frame buildings with masonry in-fill walls and reinforced concrete frames including shear walls. The procedure uses member damage functions, in terms of inter-story drift ratios, developed for the primary components: columns, beams, in-fill walls and shear walls. Analytical investigations carried out to determine the influence of a number of parameters on the damageability of components were combined with existing...
Damage detection in a sandwich composite beam using wavelet transforms
Dawood, TA; Shenoi, RA; Veres, SM; Şahin, Melin; Gunning, MJ (2003-01-01)
There is a growing interest in developing non-destructive damage detection methods for damage assessment of composite structures, especially in the aerospace and marine industries. Although damage detection of composite laminates has been widely investigated, little work has been carried out on sandwich composite configurations. A technique using the Lipschitz exponent, which is estimated by wavelet transforms, as a damage sensitive signal feature is outlined here to identify damage in sandwich composites. ...
Citation Formats
C. Karataş, B. Değerliyurt, Y. Yaman, and M. Şahin, “FIBER BRAGG GRATING SENSOR APPLICATIONS FOR STRUCTURAL HEALTH MONITORING,” 2017, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/37192.