Thermally-induced, geometrically nonlinear response of symmetrically laminated composite plates

Abstract

This paper discusses the thermally-induced geometrically nonlinear response of symmetrically laminated composite plates. The plate response is due to a temperature increase that is uniform in the plane of the plate but has a slight gradient through the thickness. The case of a completely uniform temperature increase but with an initial out-of-plane imperfection in the plate is also considered. Because they are closely allied problems, thermal buckling and postbuckling are discussed. Using variational methods in conjunction with a Rayleigh-Ritz formulation, these responses are investigated for two laminates, a (±45/0/90) s and a ( ±45 0 2 ) s , under two different simple support conditions, fixed and sliding. The effects of the principal material axes not being aligned with the edges of the plate, referred to here as material axis skewing, are also investigated. The study concludes that while differences between buckling temperatures for the two support conditions are small, support conditions can have a large influence on the thermally-induced nonlinear response. In general, plates with fixed simple supports deflect out-of-plane more than plates with sliding simple supports. In addition, support conditions can influence modal interaction. Skewing of the material axes decreases the buckling temperatures of both laminates and, like fixed support conditions, causes increased deflections. Skewing also influences modal interaction.