Experimental, analytical and numerical investigation of pultruded GFRP composite beams infilled with hybrid FRP reinforced concrete

摘要

This paper presents the experimental, analytical and numerical analyses on the behavior of the pultruded GFRP composite beams infilled with hybrid fiber reinforced concrete under four-point loading. The examined experimental variables included: (1) effect of pultruded GFRP box profile, (2) effect of conventional steel bars, GFRP bars and hybrid bars, (3) effect of externally GFRP wrapping. Pursuant to this goal, a total of 9 medium-sized beam specimens were constructed. The experimental tests were simulated using finite element models with ABAQUS program. A novel analytical method for analyzing the flexure behavior of beams has been presented. Applying the first order shear deformation beam theory and introducing auxiliary functions, the equation of motion is derived using the Hamiltonian approach. Initial stiffness, ductility, energy dissipation capacity were compared based on the load-displacement relationship. The pultruded profile significantly enhanced the behavior of traditional reinforced concrete beam and GFRP composite wrapping also considerably improved the behavior of the pultruded profile infilled with reinforced concrete beam. More importantly is that hybrid reinforcements are recommended for all cases. Moreover, detailed damage analyses are provided.