Design Optimization of Aircraft Engine-Mount Systems.
Design optimization of aircraft engine-mount systems for vibration isolation is presented. The engine is modeled as a rigid body connected to a flexible base representing the nacelle. The base (nacelle) is modeled with mass and stiffness matrices and structural damping using finite element modeling....
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| Language: | English |
| Published: |
1993
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| Online Access: | http://ezproxy.villanova.edu/login?url=https://digital.library.villanova.edu/Item/vudl:173876 |
| Summary: | Design optimization of aircraft engine-mount systems for vibration isolation is
presented. The engine is modeled as a rigid body connected to a flexible base
representing the nacelle. The base (nacelle) is modeled with mass and stiffness
matrices and structural damping using finite element modeling. The mounts are
modeled as three-dimensional springs with hysteresis damping. The objective is to
select the stiffness coefficients and orientation angles of the individual mounts in
order to minimize the transmitted forces from the engine to the nacelle. Meanwhile,
the mounts have to be stiff enough not to allow the engine deflection to exceed its
limits under static and low frequency loadings. It is shown that with an optimal
system the transmitted forces may be reduced significantly particularly when orientation
angles are also treated as design variables. The optimization problems are
solved using a constraint variable metric approach. The closed form derivatives of
the engine vibrational amplitudes with respect to design variables are derived in
order to determine the objective function gradients and consequently a more effective
optimization search technique. |
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