Environmental Engineering Reference
In-Depth Information
could then be sprayed onto virtually any substrate including metals, glass, con-
crete, and plastic. In particular, sensing skins were sprayed and embedded in glass
fiber-reinforced polymer (FRP) composites during fabrication. Laboratory char-
acterization tests were conducted, and the results verified the detection of spatially
distributed impact damage (Loyola et al.
2013b
) and drilled holes (Fig.
11.9
)
(Loyola et al.
2013a
), again, using EIT. While these bio-inspired sensing skins
demonstrated promise for SHM, more in-depth studies and larger-scale validation
tests are needed for transitioning this technology to the commercial domain.
11.5 Summary
This chapter summarizes recent developments in bio-inspired computational tools
and new technological developments for SHM. In particular, three specific areas
have been discussed. First, computational methods inspired by the BIS have been
shown to be applicable for distributed SHM sensing system. These computational
tools can be used for detecting sensor faults in the network, optimizing sensor
instrumentation strategy, or processing signals measured.
Second, mobile robotic sensors are inspired by different living being's ability to
crawl or navigate around the world. These robotic devices offer the possibility of
measuring densely distributed structural response by crawling around the host
structure. Their small size and nimbleness allow them to navigate to inaccessible
or dangerous places.
Finally, thin film-based sensors inspired by the human dermatological system
(or skin) have also been proposed and validated in the laboratory. The skin is an
extremely unique organ in which densely distributed and multi-modal sensing is
accomplished in real-time. Recent developments in nanotechnology-enabled thin
film sensors or coatings have permitted the design of artificial sensing skins. For
instance, polymeric thin films that incorporate carbon nanotubes have been shown
to be sensitive to strain. When combined with an electrical impedance tomo-
graphic spatial conductivity algorithm, spatial sensing and the detection of damage
severity and location have been verified.
Despite numerous attempts of biomimicry, most artificial systems remain
inferior to its natural counterparts and still require expensive and tedious materials
processing. The authors expect that future trends in SHM will continue to see
further developments in biologically inspired sensing systems. Not only will
technological innovations mimic biological system behavior, but also, one could
expect systems that are assembled in the same manner as in biology. This possi-
bility is becoming more realistic, especially where the advent of nanotechnology
has permitted the ''bottom-up'' assembly of molecules to form macro-scale
devices. In addition, mechanisms ranging from actuation, healing, and energy
transduction, among many others, would become integrated for advancing SHM
and for achieving next-generation resilient infrastructure systems.
Search WWH ::
Custom Search