ON SANDWICH BEAMS WITH LAMINATE FACINGS AND HONEYCOMB-CORES SUBJECTED TO HYGROTHERMAL AND MECHANICAL LOADS .3. TIMOSHENKO BEAM THEORY

Following Timoshenko beam theory [4], the present problem of a sandwich beam with laminate facings is formulated in terms of a single angular parameter psi that was first used in the Timoshenko beam equations, subsequently in the Mindlin equations for plates [4] and previously in equations for sandwich beams and plates [5,6]. The governing equations are obtained in terms of this new variable. Using energy principles and the Rayleigh-Ritz method, a new and general expression is obtained for the kinematic parameter lambda. It is shown that the earlier results obtained in References [1] and [2] are a particular case of the present formulation. In addition, the classical results are recovered from the present general results.