Strengthening Of Steel Structures Research Articles

State-of-the-art review on FRP strengthened steel structures

The use of FRP (Fibre Reinforced Polymer) to strengthen steel structures has become an attractive option which may produce confident retrofitting of existing structures. This paper reviews the following areas that have received only small coverage in previous review articles, but have developed rapidly: the bond between steel and FRP, the strengthening of steel hollow section members, and fatigue crack propagation in the FRP–Steel system. Future research topics have also been identified, such as the as bond–slip relationship, the stability of CFRP strengthened steel members, and fatigue crack propagation modeling.

Experimental and finite element analysis of a double strap joint between steel plates and normal modulus CFRP

Strengthening of steel structures using externally-bonded carbon fibre reinforced polymers ‘CFRP’ is a rapidly developing technique. This paper describes the behaviour of axially loaded flat steel plates strengthened using carbon fibre reinforced polymer sheets. Two steel plates were joined together with adhesive and followed by the application of carbon fibre sheet double strap joint with different bond lengths. The behaviour of the specimens was further investigated by using nonlinear finite element analysis to predict the failure modes and load capacity. In this study, bond failure is the dominant failure mode for normal modulus (240 GPa) CFRP bonding which closely matched the results of finite elements. The predicted ultimate loads from the FE analysis are found to be in good agreement with experimental values.

Strengthening Steel Structures and Bridges with High-Modulus Carbon Fiber-Reinforced Polymers Resin Selection and Scaled Monopole Behavior

Cost-effective solutions for the rehabilitation and strengthening of steel structures, including bridges and monopole towers, are greatly needed. Rehabilitation is often required because of cross-section losses occurring as a result of corrosion; strengthening may also be required because of changes in the use of a structure. Current techniques for strengthening steel structures have several drawbacks, including their fatigue performance and the need for ongoing maintenance owing to continued corrosion attack. The current research program makes use of a high-modulus carbon fiber for the strengthening of steel structures. This program, currently in progress, includes phases for the resin and adhesive selection for wet layup of carbon fiber sheets and bonding of precured laminate plates. Test results of the first scaled monopole tower showed a 25% increase in stiffness in the elastic range compared with the same monopole before strengthening.