| Summary: | 碩士 === 國立臺灣科技大學 === 機械工程研究所 === 84 === Panels are widely used structural elements in aerospace
structures. Therefore, lots of research works have been
published pertaining to panel flutter. In real situations,
panels may be acted upon by in-plane forces due to the
surrounding structures in addition to the aerodynamic force.
This in-plane force plays significant roles in stability of the
structures. The effect of static and periodic force has been
investigated by several researchers. But very few references
studies the effect of random in-plane force. This thesis
studies the stability of panels subjected to both aerodynamic
and random in-plane forces. The panels are modeled as a
cantilever skew plate, the aerodynamic pressure distribution is
assumed to obey the piston theory, and the in-plane force is
characterized as a Gussian white noise. Due to this in-plane
force, the plate may exhibit parametric random instability in
certain situations. In this work, the finite element
formulation is applied to obtain the discretized system
equations. The system equations are then partially uncoupled
and reduced in size by the modal truncation method. Finally the
unsmoothed and the smoothed version of the stochastic averaging
are used to calculate the system response, and the second-
moment stability criterion is utilized to determine the
stability boundary of the system. Numerical results show that
the effects of aerodynamic pressure and in-plane force are
destabilizing, and stability boundaries obtained by the
smoothed stochastic averaging are more conservative than those
obtained by the unsmoothed version.
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