696 research outputs found
Roadmap on measurement technologies for next generation structural health monitoring systems
Structural health monitoring (SHM) is the automation of the condition assessment process of an engineered system. When applied to geometrically large components or structures, such as those found in civil and aerospace infrastructure and systems, a critical challenge is in designing the sensing solution that could yield actionable information. This is a difficult task to conduct cost-effectively, because of the large surfaces under consideration and the localized nature of typical defects and damages. There have been significant research efforts in empowering conventional measurement technologies for applications to SHM in order to improve performance of the condition assessment process. Yet, the field implementation of these SHM solutions is still in its infancy, attributable to various economic and technical challenges. The objective of this Roadmap publication is to discuss modern measurement technologies that were developed for SHM purposes, along with their associated challenges and opportunities, and to provide a path to research and development efforts that could yield impactful field applications. The Roadmap is organized into four sections: distributed embedded sensing systems, distributed surface sensing systems, multifunctional materials, and remote sensing. Recognizing that many measurement technologies may overlap between sections, we define distributed sensing solutions as those that involve or imply the utilization of numbers of sensors geometrically organized within (embedded) or over (surface) the monitored component or system. Multi-functional materials are sensing solutions that combine multiple capabilities, for example those also serving structural functions. Remote sensing are solutions that are contactless, for example cell phones, drones, and satellites. It also includes the notion of remotely controlled robots
Chipless RFID sensor systems for structural health monitoring
Ph. D. ThesisDefects in metallic structures such as crack and corrosion are major sources of catastrophic
failures, and thus monitoring them is a crucial issue. As periodic inspection using the nondestructive testing and evaluation (NDT&E) techniques is slow, costly, limited in range, and
cumbersome, novel methods for in-situ structural health monitoring (SHM) are required.
Chipless radio frequency identification (RFID) is an emerging and attractive technology to
implement the internet of things (IoT) based SHM. Chipless RFID sensors are not only wireless,
passive, and low-cost as the chipped RFID counterpart, but also printable, durable, and allow
for multi-parameter sensing.
This thesis proposes the design and development of chipless RFID sensor systems for SHM,
particularly for defect detection and characterization in metallic structures. Through simulation
studies and experimental validations, novel metal-mountable chipless RFID sensors are
demonstrated with different reader configurations and methods for feature extraction, selection,
and fusion. The first contribution of this thesis is the design of a chipless RFID sensor for crack
detection and characterization based on the circular microstrip patch antenna (CMPA). The
sensor provides a 4-bit ID and a capability of indicating crack width and orientation
simultaneously using the resonance frequency shift. The second contribution is a chipless RFID
sensor designed based on the frequency selective surface (FSS) and feature fusion for corrosion
characterization. The FSS-based sensor generates multiple resonance frequency features that
can reveal corrosion progression, while feature fusion is applied to enhance the sensitivity and
reliability of the sensor. The third contribution deals with robust detection and characterization
of crack and corrosion in a realistic environment using a portable reader. A multi-resonance
chipless RFID sensor is proposed along with the implementation of a portable reader using an
ultra-wideband (UWB) radar module. Feature extraction and selection using principal
component analysis (PCA) is employed for multi-parameter evaluation.
Overall, chipless RFID sensors are small, low-profile, and can be used to quantify and
characterize surface crack and corrosion undercoating. Furthermore, the multi-resonance
characteristics of chipless RFID sensors are useful for integrating ID encoding and sensing
functionalities, enhancing the sensor performance, as well as for performing multi-parameter
analysis of defects. The demonstrated system using a portable reader shows the capability of
defects characterization from a 15-cm distance. Hence, chipless RFID sensor systems have
great potential to be an alternative sensing method for in-situ SHM.Indonesia Endowment Fund for Education
(LPDP
New advances in vehicular technology and automotive engineering
An automobile was seen as a simple accessory of luxury in the early years of the past
century. Therefore, it was an expensive asset which none of the common citizen could
afford. It was necessary to pass a long period and waiting for Henry Ford to establish
the first plants with the series fabrication. This new industrial paradigm makes easy to
the common American to acquire an automobile, either for running away or for
working purposes. Since that date, the automotive research grown exponentially to the
levels observed in the actuality. Now, the automobiles are indispensable goods; saying
with other words, the automobile is a first necessity article in a wide number of
aspects of living: for workers to allow them to move from their homes into their
workplaces, for transportation of students, for allowing the domestic women in their
home tasks, for ambulances to carry people with decease to the hospitals, for
transportation of materials, and so on, the list don’t ends. The new goal pursued by the
automotive industry is to provide electric vehicles at low cost and with high reliability.
This commitment is justified by the oil’s peak extraction on 50s of this century and also
by the necessity to reduce the emissions of CO2 to the atmosphere, as well as to reduce
the needs of this even more valuable natural resource. In order to achieve this task and
to improve the regular cars based on oil, the automotive industry is even more
concerned on doing applied research on technology and on fundamental research of
new materials. The most important idea to retain from the previous introduction is to
clarify the minds of the potential readers for the direct and indirect penetration of the
vehicles and the vehicular industry in the today’s life. In this sequence of ideas, this
book tries not only to fill a gap by presenting fresh subjects related to the vehicular
technology and to the automotive engineering but to provide guidelines for future
research.
This book account with valuable contributions from worldwide experts of
automotive’s field. The amount and type of contributions were judiciously selected to
cover a broad range of research. The reader can found the most recent and
cutting-edge sources of information divided in four major groups: electronics (power,
communications, optics, batteries, alternators and sensors), mechanics (suspension
control, torque converters, deformation analysis, structural monitoring), materials (nanotechnology, nanocomposites, lubrificants, biodegradable, composites, structural
monitoring) and manufacturing (supply chains).
We are sure that you will enjoy this book and will profit with the technical and
scientific contents. To finish, we are thankful to all of those who contributed to this
book and who made it possible.info:eu-repo/semantics/publishedVersio
Recommended from our members
ReSCon '09, Research Student Conference: Book of Abstracts
The second SED Research Student Conference (ReSCon2009) was hosted over three days, 22-24 June 2009, in the Lecture Centre at Brunel University. The conference consisted of technical presentations, a poster session and social events. The abstracts and presentations were the result of ongoing research by postgraduate research students from the School of Engineering and Design at Brunel University. The conference is held annually, and ReSCon plays a key role in contributing to research and innovations within the School
Microwave NDT&E using open-ended waveguide probe for multilayered structures
Ph. D. Thesis.Microwave NDT&E has been proved to be suitable for inspecting of dielectric structures due
to low attenuation in dielectric materials and free-space. However, the microwave responses
from multilayered structures are complex as an interrogation of scattering electromagnetic
waves among the layers and defects. In many practical applications, electromagnetic analysis
based on analytic- and forward structural models cannot be generalised since the defect shape
and properties are usually unknown and hidden beneath the surface layer.
This research proposes the design and implementation of microwave NDT&E system for
inspection of multilayered structures. Standard microwave open-ended rectangular waveguides
in X, Ku and K bands (frequency range between 8-26.5 GHz) and vector network analyser
(VNA) generating sweep frequency of wideband monochromatic waves have been used to
obtain reflection coefficient responses over three types of challenging multilayered samples: (1)
corrosion progression under coating, (2) woven carbon fibre reinforced polymer (CFRP) with
impact damages, and (3) thermal coated glass fibre reinforced polymer (GFRP) pipe with inner
flat-bottom holes. The obtained data are analysed by the selected feature extraction method
extracting informative features and verify with the sample parameters (defect parameters). In
addition, visualisation methods are utilised to improve the presentation of the defects and
material structures resulting in a better interpretation for quantitative evaluation.
The contributions of this project are summarised as follows: (1) implementation of microwave
NDT&E scanning system using open-ended waveguide with the highest resolution of 0.1mm x
0.1 mm, based on the NDT applications for the three aforementioned samples; (2) corrosion
stages of steel corrosion under coating have been successfully characterised by the principal
component analysis (PCA) method; (3) A frequency selective based PCA feature has been used
to visualise the impact damage at different impact energies with elimination of woven texture
influences; (4) PCA and SAR (synthetic aperture radar) tomography together with time-offlight extraction, have been used for detection and quantitative evaluation of flat-bottom hole
defects (i.e., location, size and depth).
The results conclude that the proposed microwave NDT&E system can be used for detection
and evaluation of multilayered structures, which its major contributions are follows.
(1) The early stages (0-12month) of steel corrosion undercoating has been successfully
characterised by mean of spectral responses from microwave opened rectangular
waveguide probe and PCA.
(2) The detection of low energy impact damages on CFRP as low as 4 Joules has been
archived with microwave opened rectangular waveguide probe raster scan together with
SAR imaging and PCA for feature extraction methods.
(3) The inner flat-bottom holes beneath the thermal coated GFRP up to 11.5 mm depth has
been successfully quantitative evaluated by open-ended waveguide raster scan using
PCA and 3-D reconstruction based on SAR tomography techniques. The evaluation
includes location, sizing and depth.
Nevertheless, the major downside of feature quantities extracted from statistically based
methods such as PCA, is it intensely relies on the correlation of the input dataset, and thus
hardly link them with the physical parameters of the test sample, in particular, the complex
composite architectures. Therefore, there are still challenges of feature extraction and
quantitative evaluation to accurately determine the essential parameters from the samples. This
can be achieved by a future investigation of multiple features fusion and complementary
features.Ministry of Science and Technology of Royal Thai Government
and Office of Educational Affairs, the Royal Thai Embass
Imaging of buried utilities by ultra wideband sensory systems
Third-party damage to the buried infrastructure like natural gas pipelines, water distribution pipelines and fiber optic cables are estimated at 400 billion, however, non-destructive condition assessment technologies capable of providing quantifiable data regarding the structural integrity of our buried assets in a cost-effective manner are lacking. Both of these areas were recently identified several U.S. federal agencies as \u27critical national need\u27. In this research ultra wideband (UWB) time-domain radar technology was adopted in the development of sensory systems for the imaging of buried utilities, with focus on two key applications. The first was the development of a sensory system for damage avoidance of buried pipes and conduits during excavations. A sensory system which can be accommodated within common excavator buckets was designed, fabricated and subjected to laboratory and full-scale testing. The sensor is located at the cutting edge (teeth), detecting the presence of buried utilities ahead of the cutting teeth. That information can be used to alert the operator in real-time, thus avoiding damage to the buried utility. The second application focused on a sensory system that is capable of detecting structural defects within the wall of buried structures as well as voids in the soil-envelope encasing the structure. This ultra wideband sensory system is designed to be mounted on the robotic transporter that travels within the pipeline while collecting data around the entire circumference. The proposed approach was validated via 3-D numerical simulation as well as full-scale experimental testing
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