C haptEr 9 design Environments and systems
306
a mix that are filled with materials that harden when exposed to a
catalyst. Developing cracks are intercepted by these encapsulations
and ruptured. The released materials act to fill cracks and interact
with catalysts that in turn cause the released material to harden.
Self-healing materials are discussed in more detail in Section 10.2.
The use of nanoparticles is also expected to have benefits that go
beyond mechanical improvements. As discussed in Chapter 11 on
environmental issues, some forecasts suggest enormous potential
reductions in released carbon dioxide levels because of potentially
reduced kiln temperatures and durations that occur during processing. Due to the enormous volumes of cement produced in the world,
quantities could eventually be huge if nanomaterials are extensively
used. Strength improvements also generally yield smaller required
overall quantities.
damage monitoring and responsive structures
Nanotechnologies offer interesting promises within the realm of
active structural health monitoring (e.g., damage assessment) and
that of active responsive structural systems. In general, all active
structural systems include a sensory capability for detecting and
communicating some phenomena induced by a force environment, such as deformations, deflections, cracks, and vibrations. A
more sophisticated and responsive system would include a control
system that interprets sensory inputs and causes some actuation
mechanism to provide a response, typically one that mitigates
undesired phenomena.
Damage assessment needs are a common motivator for using active
systems. Often called structural health monitoring systems, a number
of approaches are already in use, depending on the phenomena of
interest. Embedded fiber or piezoelectric technologies, for example,
can be used to assess breaks, sharp bends, strains, and vibrations.
Magnorestrictive and other smart materials can be used as well.
Here the intent is primarily to provide information about the type
and location of structural damage in a structure. The capabilities of
nanotechnologies to serve as sensors opens the door for applications in this area.
Systems that not only detect various phenomena but provide
responses as well include many different types of deflection or vibration control devices. The control of vibratory phenomena through
damping actions is central to the performance of many structures,
ranging from the very large scale to the smaller scale. At the large
scale is a strong need to mitigate the highly damaging dynamic
306
a mix that are filled with materials that harden when exposed to a
catalyst. Developing cracks are intercepted by these encapsulations
and ruptured. The released materials act to fill cracks and interact
with catalysts that in turn cause the released material to harden.
Self-healing materials are discussed in more detail in Section 10.2.
The use of nanoparticles is also expected to have benefits that go
beyond mechanical improvements. As discussed in Chapter 11 on
environmental issues, some forecasts suggest enormous potential
reductions in released carbon dioxide levels because of potentially
reduced kiln temperatures and durations that occur during processing. Due to the enormous volumes of cement produced in the world,
quantities could eventually be huge if nanomaterials are extensively
used. Strength improvements also generally yield smaller required
overall quantities.
damage monitoring and responsive structures
Nanotechnologies offer interesting promises within the realm of
active structural health monitoring (e.g., damage assessment) and
that of active responsive structural systems. In general, all active
structural systems include a sensory capability for detecting and
communicating some phenomena induced by a force environment, such as deformations, deflections, cracks, and vibrations. A
more sophisticated and responsive system would include a control
system that interprets sensory inputs and causes some actuation
mechanism to provide a response, typically one that mitigates
undesired phenomena.
Damage assessment needs are a common motivator for using active
systems. Often called structural health monitoring systems, a number
of approaches are already in use, depending on the phenomena of
interest. Embedded fiber or piezoelectric technologies, for example,
can be used to assess breaks, sharp bends, strains, and vibrations.
Magnorestrictive and other smart materials can be used as well.
Here the intent is primarily to provide information about the type
and location of structural damage in a structure. The capabilities of
nanotechnologies to serve as sensors opens the door for applications in this area.
Systems that not only detect various phenomena but provide
responses as well include many different types of deflection or vibration control devices. The control of vibratory phenomena through
damping actions is central to the performance of many structures,
ranging from the very large scale to the smaller scale. At the large
scale is a strong need to mitigate the highly damaging dynamic