Titel_SS06

System 1: „Highway network“
Exposure:

• Traffic


• Axle load


• HGV traffic
  ...

System 2: „Bridge“ Exposure:

• Windload


• Axle load


• Vehicle impact
  ...

Network failure Road closure Bridge failure support linksFailure of Failure of the cable of wiresFailure

System 3: „Wire“

consequencesindirect consequencesdirect consequencesindirect direct

consequences

indirect

consequences consequencesdirect

F

Exposure:

• Wind-Rain induced
  vibrations


• Corrosion


• Fatigue
  ...

Vulnerability

Vulnerability Vulnerability

Robustness Robustness

Robustness

(^) cScID 21 (, ())k DC cCDij^ cScID 32 (, ())k DC cCD ij
Figure 4.5: Generic system characterization at different scales in terms of exposure, vulnerability and
robustness.
Exposure and hazards
The exposure to a system is defined as all possible endogenous and exogenous effects with
potential consequences for the considered system. A probabilistic characterization of the
exposure to a system requires a joint probabilistic model for all relevant effects relative to
time and space.
Vulnerability
The vulnerability of a system is related to the direct consequences caused by the damages of
the constituents of a system for a given exposure event. The damage of the constituents of a
system represents the damage state of the system. In risk terms the vulnerability of a system is
defined through the risk associated with all possible direct consequences integrated (or
summed up) over all possible exposure events.
Robustness
The robustness of a system is related to the ability of a considered system to sustain a given
damage state subject to the prevailing exposure conditions and thereby limit the consequences
of exposure events to the direct consequences. It is of importance to note that the indirect
consequences for a system not only depend on the damage state but also the exposure of the
damaged system. When the robustness of a system is assessed it is thus necessary to assess
the probability of indirect consequences as an expected value over all possible damage states
and exposure events. A conditional robustness may be defined through the robustness
conditional on a given exposure and or a given damage state.