| This thesis presents the results of an experimental and analytical investigation into the flexural-torsional buckling behavior of fiber reinforced polymeric (FRP) T-shaped pultruded structural members subjected to axial compression. These members were made of a vinylester resin reinforced with E-glass unidirectional rovings and continuous strand mats (CSM) in some cases, and a polyester resin reinforced with E-glass unidirectional rovings and [−45°/90°/+45°] stitched fabrics (SF) in other cases.; In the experimental part, nine E-glass/vinylester and eight E-glass/polyester pultruded T-shaped members were tested under axial compression. The experimental boundary conditions consisted of two sets of one directional knife edge fixture that permits end rotation about the axis of symmetry of the T-section. The applied load, axial shortening, lateral displacements, and twisting were measured using a load cell, an LVDT, and potentiometers. In the analytical part, an energy solution, using the Ritz method, to the buckling problem of a pultruded T-section under uniform compression was derived. The solution accounts for bending-twisting and bending-extension coupling effects. Results obtained from the analytical solution were compared to those estimated from experiments. It was found that the ratios of the experimental to analytical results were in the range of 1.00 to 1.32. Finite element (FE) solutions were obtained using ABAQUS, and the ratios of the experimental to FE solutions were in the range of 1.07 to 1.38. |
