Local buckling coefficient of thin-walled pultruded FRP compression members

Abstract

Recently there has been an increased demand in the use of FRP materials as load-bearing structural elements for the civil engineering applications, since FRP composite materials offer superior properties to conventional structural materials used in civil engineering structures. Among various production techniques, the pultrusion process has enabled the production of structural profiles with large cross sections at relatively low cost. Pultruded structural members are generally manufactured in the form of thin-walled member composed of plate elements and material properties can often be assumed as orthotropic. Due to the relatively low geometrical stiffness, often combined with low elastic modulus, the design of pultruded profiles is governed by the deflection or buckling rather than the material strength. In this paper, the elastic local buckling coefficient of the pultruded structural member having L-, T- and box-shape under the uniform in-plane compression was investigated and approximate equation to find the local buckling strength was proposed by using the classical orthotropic plate theory and energy method. The suggested equation can be used in the development of the design criteria and local buckling analysis of pultruded structural members.