Study of Structural Response and Failure Characteristics of Thin Walled Flanged FRP Beams

Abstract

The applications of fiber reinforced polymer (FRP) products are increasing in the construction sectors due to its versatile properties such as lightness, resilience to corrosion and ease of installation. They have been found to have almost unlimited usefulness in all segments of the construction industries such as FRP structural elements, bridge repair, cable-stayed bridge, structural strengthening, etc. The FRP products has attracted great attention due to its high specific stiffness, specific strength, non-corrodible characteristics and chemically inert properties. FRP beams made using pultrusion process consists of different layers of laminae. It is very important to determine the properties of each layer and panels (flange and web) for the optimal design of FRP beams for specific applications. Young s modulus of elasticity and shear modulus of the beams are determined by different test methods such as tensile testing of coupons, three-point bending testing of coupons and beams, and four-point bending test of beams. Further, the stiffness of beams is evaluated from approximate classical and mechanics of laminated beam theories. In order to check the accuracy of the stiffness, Timoshenko s beam theory is used to determine the load-deflection response of the beam with predicted stiffness and compared with that obtained from experimental three-point bending test. It is observed that flexural responses obtained using stiffness predicted from four-point bending test and theories give the good agreement of results. Hence, for further parametric study on beams, mechanics of laminated beam theory is used to determine the flexural response of beams having different types of laminae. newlineFlexural response of the beams having imperfection in the geometry (i.e., one of the flange is not perpendicular to the web) is predicted under three-point bending. It is observed that due to imperfection in the flange, beam deflects in lateral direction which leads to failure of the web-flange junction. Further, the flexural response of FR