A Study on Improving the Mechanical Behaviors of the Pultruded GFRP Composite Material Members

Abstract

This study focuses on improving the mechanical behaviors of pultruded glass fiber-reinforced polymers (GFRP) composite material. A combined GFRP member was prepared by the insertion of a second GFRP tube inside the prototype GFRP member and then filling the compartment with epoxy resin mortar to combine both members. Analysis of the combined member was performed to consider improvement of the stiffness and strength of the material to meet design requirements. Four different types of GFRP deck specimens and five different types of GFRP beam specimens were investigated by performing the three-point bending test to obtain their ultimate strength, ultimate displacement, stiffness, and corresponding failure modes. Observations from the experiment showed that infilling the rectangular GFRP tube member can effectively increase the GFRP specimen’s stiffness and ultimate strength. Finally, the Euler beam and Timoshenko beam theories combined with the transformed section method were used to obtain the stiffness of the combined GFRP members, and then compare those stiffness with the experimental results.