Local buckling and post-critical behavior of thin-walled composite channel section columns

Abstract

This work presents a study of the behavior, performance and failure of thinwalled composite channel section columns. The study is carried-out using nonlinear finite element models of laminated columns, including geometric imperfections and material failure, as well as approximate analytical solutions based on the Classical Lamination Theory. The accuracy of the numerical model is assessed using experimental results available in the literature and very good results were obtained. The results show the influence of the column layup and wall thickness on the structural behavior of laminated columns, including the buckling mode and ultimate failure load. Finally, the numerical model is used to assess the accuracy of approximate closed-form expressions for evaluation of the local buckling loads of composite channel section columns.

A Numerical Study of the Effect of Component Dimensions on the Critical Buckling Load of a GFRP Composite Strut under Uniaxial Compression

“…The results indicate that the post-critical load significantly decreased when the imperfection amplitude increased from 0.05h to 0.12h. This effect reflected the real behavior of the strut and agreed with the results reported in the literature [16]. These agreements in verification indicate that the current FE model could be utilized for further investigation.…”

“…where σ and ε are stress and strain vectors in the local coordinate system, respectively; Q denotes the elastic constitutive matrix; 21 , and G 12 are the material elastic parameters, where. In the num v 21 = v 12 E 1 /E 2 erical analysis, the local stress-strain relationship should be transformed into the global coordinate system [16]. The stress in the global system can now be expressed as:…”

“…Conducting the experiment is a powerful approach for researching new related buckling problems or new types of composite materials [13][14][15]. However, it requires a lot of resources and is often costly [16]. One of the main concerns in the composite industry is to reduce these experimental costs while still obtaining extensive investigation results.…”

“…Moreover, in practical design, extended studies also need to be applicable. A number of numerical models have been developed for the buckling analysis of the GFRP composite materials, especially for the channel-section shape column, such as local buckling and post-buckling behavior [16,20]; progressive failure analysis collapse of the GFRP column [21,22]; buckling, post-buckling, and failure analysis of pre-damaged GFRP column [17,23]; etc. However, in that research, only one certain dimension of the GFRP column is selected for the investigation; some of them considered the change in dimension only through increasing or decreasing the number of laminate layers.…”

Review on Local Buckling of Hollow Box FRP Profiles in Civil Structural Applications

“…Increasing this ratio three times was found to decrease the buckling strength down to 42.8% under compression while it will increase the buckling strength up to 57.0% under bending. Moreover, the optimal cross-sectional aspect ratios of open-section PFRP profiles were investigated for column [ 65 , 109 , 111 ] and beam [ 65 , 82 ] applications. In addition, the interaction between the cross-sectional aspect ratio and the layup properties was studied for box [ 63 ] and I-shape [ 64 ] GFRP columns.…”