structural health issues

1. Structural Health Monitoring-2

2. • Design uncertainties
– Loading conditions
• Manufacturing uncertainties
• Material variations
• Environmental effects
• Aging Infrastructures
– Civil infrastructures
– Spacecrafts
Why Do Disaster Happen?

3. Conventional Structural Systems
Conventional Structural Systems are
dumb, very dumb
– Designed to achieve a set of
intended functions under pre-
selected loads and forces.
– Large safety factor is employed
to account for the uncertainty in
external loads
– Unable to adapt to structural
changes and to varying usage
patterns and loading
conditions.
Both pictures were taken from
the 1995 Kobe Earthquake
Design, Build, and Cross-your-fingers

4. Future Structural Systems
“Smart” Structures-structures
that are able to sense and
response/adapt to changes
in their environment
Characteristics of SS
– Integrated with many
sensors and control
devices through
information network
– To achieve an enhanced
performance at a reduced
life-cycle cost
Image courtesy of USA Today & Ken P. Chong at NSF

5. Biological Analogy to Smart Structural
System
A smart structural system can be considered as a mimicking
of biological systems, possessing its own sensory and
nervous systems, brain, and muscular system, with the goal
of being autonomous and adaptable as living things
Information
Processing (brain)
Actuators
(Muscular)
Sensors
(visual, olfactory,
hearing,
mechanosensory)
Courtesy of T. Kobori, Kajima Corp.

6. Structural Health Monitoring

7. Components of Structural Health
Monitoring System
Networked
Sensors
Control &
Actuator
Information
Processing
Structural
System
SSS
Smart
Materials