Finite Element Model of Composite Connections Strengthened with CFRP Laminates

Abstract

Carbon Fiber Reinforced Polymer (CFRP) materials are being widely used for structural applications. Despite the relatively high cost of the CFRP materials, their high strength-to-weight ratio and corrosion resistance as well as easy handling and installation have made them widely popular for different civil engineering applications where increased strength and/or ductility is important. This thesis investigates the moment-rotational response of an endplate composite connection including strengthening of the slab by using different sizes and thickness of CFRP sheets in hogging moment regions and different reinforcement bar ratios by using finite element simulations. A three dimensional non-linear model is developed in ANSYS to study the feasibility of decreasing the reinforcing bars in the presence of the CFRP laminate in hogging moment regions of the slab. The verification of the analysis is carried out to calibrate the un-strengthened model by available experimental results obtained from a series of composite connection tests as reported by other researchers. The moment resistance for the partial depth endplate composite connection obtained by ANSYS 12.1 software is found to be very close to the corresponding laboratory test value. From the results it can be observed that applying CFRP sheets to the tension face of composite slab can reduce the amount of steel reinforcement bars required for flexural strength of composite connections.