Civil Engineering Reference
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5.8 Conclusion
SFEM is used to evaluate sensitivity index of design space parameters with respect
to the selected performance function and probability of failure of satellite structure
under static and thermal loads. It is important for the design engineer to determine
the structure response sensitivity to the random design variables (geometrical,
material properties, loads). If the uncertainty in one of the design space variables
has significant effect on the selected performance function, then it is important to
reduce its uncertainty by collecting more data using testing or increase the value of
safety factor. This will improve the design reliability and could help to reduce cost.
Reducing cost can be achieved by assigning different safety factors for the design
space parameters based on their uncertainty and sensitivity index. Sensitivity
analysis can help the designer to eliminate the variables that have lower sensitivity
index from the design optimization process. The response sensitivities are com-
puted in this paper using the finite difference approach, by perturbing each design
variable and computing the change in the performance function. The proposed
approach is applied after simplifying the structure to a group of 3D beam elements
and ignoring the plate effect.
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