Non-linear multi-mode buckling of non-symmetric FML/FGM thin-walled columns with open cross-sections under compression

Abstract

Current paper is the second part of Kolakowski Z, Mania RJ paper entitled: “Influence of the coupling matrix B on the interactive buckling of FML-FGM columns with closed cross-section under axial compression”, Composite Structures, in press. The problem of non-linear multi-mode buckling of thin-walled columns with open cross-sections made of Functionally Graded Materials (FGMs) and Fibre Metal Laminate (FML) was discussed. FGM layers are a thermal barrier, whereas the FML composite provides rigidity and strength. This new hybrid thin-walled structure is very interesting but there are no interactive buckling solutions.The non-linear problem of buckling was solved with the analytical-numerical method (ANM) based on Koiter’s theory. An interaction of global buckling mode with many different local buckling modes was discussed. A plate model and the classical laminate theory are used to define government relations. The differential equilibrium equations were obtained with a variational method. Each column was made of an FML sublayer, a single AL-TiC-type FGM layer and/or a TiC ceramic layer. The FML sublayer consisted of two outer aluminium layers and even carbon-epoxy prepreg interlayers. The layup configuration of the FML/FGM composite is non-symmetric, so the coupling matrix B is non-trivial. Simply supported columns are under mechanical compression only.