AN INVESTIGATION OF NONLINEAR DYNAMICS OF MULTILAYERED PLATES ACCOUNTING FOR C-Z(0) REQUIREMENTS

Concerning accurate modelling of multilayered thick plates, this paper investigates both zig-zag and interlaminar continuity effects, i.e. C -z(o) requirements, in the non-linear (in von Karman sense) dynamics f ields. The used model, denoted elsewhere by the acronym RMZC (Reissner -Mindlin, Zig-zag, Continuity) Furnishes, as a particular case, both t he CLT (Classical Lamination Theory) and the FSDT (First-order Shear D eformation Theory). Efficient finite element plate formulations of Rei ssner-Mindlin type have been introduced to derive approximate governin g equations, which are then solved by employing Newton-Raphson lineari zation and Newmark time-integration methods. Different geometries, loa ding conditions and layouts have been considered in the numerical part . As for the static case, it has been confirmed that the RMZC model im proves the FSDT results in the analysis of large amplitude vibrations of thick plates. In the case of thin plates, both models have led to s imilar results. Several examples have shown that CLT, as well as linea r approximation, can lead to a poor description of the non-linear dyna mical behaviour of laminated plates. Furthermore, by considering a ste ady-state solution of damped harmonic forced excitation, it has been f ound that in the case of unsymmetrically laminated plates, the linear solution can over- or underestimate the non-linear results, depending both on the magnitude and type of the applied loading. (C) 1998 Elsevi er Science Ltd. All rights reserved.