High modulus carbon fiber materials for retrofit of steel structures and bridges
This paper summarizes the research work dealing with the use of high modulus carbon fiber reinforced polymer (HM CFRP) materials for the retrofit of steel structures and bridges. The research work included selection of an appropriate adhesive for bonding HM CFRP materials to steel and the performance of Large-scale steel-concrete composite beams tested to examine the behavior of different strengthening schemes. The research findings demonstrate the effectiveness of the proposed HM CFRP strengthening system.
Nonlinear Behavior of Steel-Concrete Composite Beams Curved in Plane with CFRP Strips Bonding
This paper deals with the behavior of structural steel-concrete composite beams curved in plane. The analytical investigation included the use of three dimensional nonlinear finite elements to model the performance of the composite beams strengthened with CFRP strips by using (ANSYS 11.0) computer program. The numerical results showed very good agreement with the experimental results reach to 100% before the strengthening, while the increase in strength after the curved strengthened with CFRP strips 32% for the curve beam with L/R equal to 0.05 and 48% for the curve beam with L/R equal to 0.10 and 53% for the curve beam with L/R equal to 0.25.
Evaluation of buckling load and dynamic performance of steel shear wall retrofitted with strips made of shape memory alloy
One of the most imperfections of the steel shear wall is out of plane displacements that cause severe damage in both structural and non-structural elements. In this paper, the effects of shape-memory alloys on steel shear walls are investigated. First, a numerical analysis using the finite element method in ABAQUS software has been carried out according to an experimental test. The results of the numerical analysis have been verified with experimental results. Next, shape-memory alloy fibers have been added vertically and horizontally to various parts of the steel shear wall. The results show that retrofitting with the shape-memory alloy reduces the out-of-plane displacement of the steel shear wall under both cyclic and seismic loadings. Besides, the buckling load in the steel shear wall increases when it is retrofitted with the shape-memory alloy. Also, the total out-of-plane movement (accumulated absolute displacements) of the steel shear wall and non-structural damage are controlled by the characteristic of a shape-memory alloy material called “super-elastic”.