Vibration analysis to composite panels in thermal environment

Composite panels are commonly applied to high speed aircraft, where aerodynamic heating effect must be considered, thus the vibration analysis of composite 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 assumption of uncoupled thermal-structural properties and nonlinear von Karman large-deflection strain-displacement relationship, the vibration equation is established 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 frequencies of the composite panel lower mainly with the impact of thermal induced stiffness term rather than that of thermal induced variation of material properties.