NASA Technical Reports Server (NTRS) 20020080112: Combining Sense and Intelligence for Smart Structures

2 Pages·0.09 MB·English

by  NASA Technical Reports Server (NTRS)

Combining Sense and Intelligence
for Smarter Structures
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n an effort to keep pace with the demands module that is rugged, compact and light-weight,
FS of a continuously growing society and a new and immune to electromagnetic interference.
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NO millennium, builders, engineers, and archi- These features make the I*Sense multisensor
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S tects are constructing taller skyscrapers, longer arrays favorable for smart structure applications,
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TS bridges, and faster aircraft. But with these savvy including smart buildings, bridges, highways,
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NE technological advancements comes the need for dams, power plants, ships, and oil tankers, as
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B a superior safety system that can provide real- well as space vehicles, space stations, and other
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CI time structural data to prevent the possibility of space structures. For instance, the system can be
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ME catastrophic failure. Intelligent Fiber Optic used as an early warning and detection device,
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O Systems (IFOS), Inc., a leading photonic with alarms being set to monitor the maximum
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company located in Sunnyvale, California, allowable strain and stress values at various
believes it has a viable solution: the company points of a given structure.
has positioned itself for rapid growth in the IFOS continued to enhance the product
optical networking market with the development design even further by adding multiple sensors
of the I*Sense™ 14000 Fiber-Optic Spectral on a single fiber. The I*Sense 14000 model
Monitoring System, a high-speed, high-precision, makes parallel, high-bandwidth measurement of
modular measurement application. signals within an array of multiplexed optical
IFOS developed the I*Sense technology with sensors technically possible and economical. The
assistance from a NASA Langley Research technology has the capability to monitor optical
Center Small Business Innovation Research systems that are up to several kilometers from
(SBIR) contract. NASA and IFOS collaborated the unit on a single 250-micrometer diameter
to create sensing network designs that have high optical fiber. Moreover, the system’s data
sensitivity, low power consumption, and signifi- acquisition software and hardware permit the
cant potential for mass production. The joint- monitoring of four wavelengths per fiber
research effort led to the development of a module, and are expandable to accommodate
The I*Sense™ 14000
detects strain and stress
values of smart structures,
such as bridges, buildings,
and dams.
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The acquisition software for
the I*Sense™ 14000 returns FS
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real-time sensor feedback to a N
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monitoring systems with multiple module planning to advance the I*Sense technology
configurations; all units are compatible with even further with applications in temperature
personal computers equipped with Microsoft® and pressure sensing. The company notes that
Windows® operating systems. The company is the I*Sense system’s fiber Bragg grating building-
also pressing ahead with its latest commercial blocks (wavelength-selective reflectors embedded
model, the I*Sense 18000, which allows for inside the fiber through a specialized fabrication
parallel, high-bandwidth measurement of eight process) could potentially be used with materials
multiplexed optical sensors. that are electrostrictive, magnetostrictive, and
The aerospace industry has expressed consid- piezoelectric to act as transducers for measure-
erable interest in employing I*Sense systems to ment of electric and magnetic fields, voltages,
monitor operational parameters and structural acceleration, velocity, displacement, and vibration
integrity. More specifically, aerospace companies frequency. Temperature-sensitive environments,
are considering utilization of the sensing systems such as greenhouses, arctic and marine regions,
with composite materials to reduce the cost and and space, may also benefit greatly from the
weight of airframes. According to IFOS, its monitoring capabilities of I*Sense. ❖
fiber sensors offer distinct advantages over
electrical sensors, ultimately making the I*Sense I*Sense™ is a trademark of Intelligent Fiber Optic Systems,
networks a perfect match for smart skins on Inc.
both aircraft and space vehicles, as well as
Microsoft® and Windows® are registered trademarks of
many other aerospace structural health monitor- Microsoft Corporation.
ing applications, including supersonic transport.
While IFOS’ focus to date has been on
multiplexed strain sensing applications, it is
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