Hybrid versus FR laminate channel section columns - Buckling and postbuckling behaviour

The paper deals with buckling and postbuckling behaviour of short columns of channel cross section subjected to uniform axial compression. Considered columns are made as 8 layers GFRP laminate with different layer arrangement and as FML with different laminate layers configurations. The comparison of buckling load, postbuckling behaviour and failure load for column made with hybrid composite and GFR laminate have been made. The experimental test and numerical calculation have been performed. The experimental buckling tests were conducted using universal machine equipped with special self-aligning grips. Additionally the digital image correlation system (Aramis) has been used for non-contact 3D displacement measurement. Numerical analysis were condthed using ANSYS software. The numerical model was prepared with boundary conditions corresponding to the laboratory test stand. The linear buckling analysis and then nonlinear analysis have been performed. Thus the buckling load with corresponding buckling mode and postbuckling behaviour have been determined. Applying failure criteria and employing progressive damage analysis the failure load have been estimated as well. The results for real structures and ideal model have been compared. The advantage and disadvantage of the type of material used for columns according to structure behaviour have been presented. Additionally, the difficulties and differences in FE modelling of postbuckling behaviour and failure phenomenon of columns made of FML and GFRP laminate have been discussed. (C) 2016 Elsevier Ltd. All rights reserved.