Flexural Strength of Carbon Fiber Reinforced Polymer Repaired Cracked Rectangular Hollow Section Steel Beams

Abstract

The flexural behavior of rectangular hollow section (RHS) steel beams with initial crack strengthened externally with carbon fiber reinforced polymer (CFRP) plates was studied. Eight specimens were tested under three-point loading to failure. The experimental program included three beams as control specimens and five beams strengthened with CFRP plates with or without prestressing. The load deflection curves were graphed and failure patterns were observed. The yield loads and ultimate loads with or without repairing were compared together with the strain distributions of the CFRP plate. It was concluded that yield loads of cracked beams could be enhanced with repairing. Meanwhile, the ultimate loads were increased to some extent. The effect of repair became significant with the increase of the initial crack depth. The failure patterns of the repaired specimens were similar to those of the control ones. Mechanical clamping at the CFRP plate ends was necessary to avoid premature peeling between the CFRP plate and the steel beam. The stress levels in CFRP plates were relatively low during the tests. The use of prestressing could improve the utilization efficiency of CFRP plates. It could be concluded that the patching repair could be used to restore the load bearing capacity of the deficient steel beams.

Structural Design and Mechanical Performance Analysis of Carbon Fiber Closed Fixtures for UHV Transmission Lines

“…Carbon fiber outer cladding structure is shown in Figure 12, where θ i indicates the lay angle. e function of this type structure is similar to that of I-beam [8]. e upper and lower horizontal layers are similar to the webs of I-beams, which is to increase the bending strength and shear strength of the whole structure.…”

“…erefore, in order to meet the mechanical performance requirements, carbon fiber laminate structures need to be elaborated. A quasi-isotropic pavement structure with 0°, ±45°, and 90°cross-arrangement is proposed to meet the mechanical performance requirements of some bent and sheared parts [8][9][10][11]. And to reduce the weight and improve the flexural rigidity and the stability, a carbon fiber foam sandwich structure is discussed in the aerospace [12][13][14][15].…”

Structural Behavior of Large-Scale Hollow Section RC Beams and Strength Enhancement Using Carbon Fiber Reinforced Polymer (CFRP) Composites

“…Its failure was ductile limited to CFRP debonding and experienced the highest amount of concrete crushing at its midspan in this group (see Figure 14 ). In the past, sudden deboning of CFRP from the RS beams has been also reported in many studies [ 26 , 29 ].…”

“…Chen et al [ 29 ] carried out investigations on the influence of CFRP plates in restoring structural properties of rectangular hollow beams. They tested eight beams under 3-point loading out of which three beams were kept as controlled and five beams strengthened with CFRP plates with and without prestressing.…”

Experimental Investigation on the Buckling Capacity of Angle Steel Strengthened at Both Legs Using VaRTM-Processed Unbonded CFRP Laminates

“…Indeed, the externally bonded strengthening technique is effective for enhancing the performance of steel structures. It has been convincingly proven that this technique is able to increase: the compression capacity of short steel members [ 11 , 12 , 13 ], flexural capacity of steel beams [ 14 , 15 , 16 , 17 , 18 ], torsional capacity of steel members [ 19 , 20 ], load bearing capacity of steel shear wall [ 21 , 22 , 23 ], tensile capacity of steel plates [ 24 , 25 , 26 , 27 , 28 ], and also buckling capacity of long steel columns [ 29 , 30 , 31 ]. However, this strengthening technique is considered to have drawbacks.…”