Vibration Analysis to Composite Panels in Thermal Environment
Xia Wei,Yang Zhichun
(School of Aeronautics, Northwestern Polytechnical University, Xi'an 710072)

Abstract: Composite panels are commonly applied to high speed aircraft, where a erodynamic heating effect must be considered, thus the vibration analysis of com posite panel in thermal environment is an attractive topic of aerothermoelasticity. A linearized finite element approach is proposed to determine the vibration characteristics of composite panels under thermal conditions. With the assumptio n of uncoupled thermal-structural properties and nonlinear von Karman large-deflection strain-displacement relationship, the vibration equation is establish ed by Hamilton variation principle. To obtain the finite element equations of thermal vibration, the Mindlin plate element (MIN3) is used so that the transverse shear effect can be considered, and the thermal effect is represented by an equivalent thermal stiffness term and a thermal load term. Numerical examples are presented and the comparisons of the simulated results with existing ones confirm the validity and accuracy of this method. It is concluded that the natural freq uencies of the composite panel lower mainly with the impact of thermal induceds tiffness term rather than that of thermal induced variation of material properties.
Keywords: composite panels, thermal environment, natural vibration characteristi cs.