Different types of fiber optic sensors based on glass or
polymeric fibers are used to evaluate material behavior or to monitor the
integrity and long-term stability of load-bearing structure components.
Fiber-optic sensors have been established as a new and
innovative measurement technology in very different fields, such as material
science, civil engineering, light-weight structures, geotechnical areas as well
as chemical and high-voltage substations. Very often, mechanical quantities
such as deformation, strain or vibration are requested. However, measurement of
chemical quantities in materials and structure components, such as pH value in
steel reinforced concrete members also provides information about the integrity
of concrete structures.
A special fiber-optic chemical sensor for monitoring the
alkaline state (pH value) of the cementitious matrix in steel-reinforced
concrete structures with the purpose of early detection of corrosion-initiating
factors is described. The paper presents the use of several fiber-optic sensor
technologies in engineering.
One example concerns the use of highly resolving
concrete-embeddable fiber Fabry-Perot acoustic emission (AE) sensors for the
assessment of the bearing behaviour of large concrete piles in existing
foundations or during and after its installation. Another example concerns
fiber Bragg grating (FBG) sensors attached to anchor steels (micro piles) to
measure the strain distribution in loaded soil anchors.
Polymer optical fibers (POF) can be — because of their high
elasticity and high ultimate strain — well integrated into textiles to monitor
their deformation behaviour. Such “intelligent” textiles are capable of
monitoring displacement of soil or slopes, critical mechanical deformation in
geotechnical structures (dikes, dams, and embankments) as well as in masonry
structures during and after earthquakes.
没有评论:
发表评论