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.
Bond Behavior of a CFRP Strengthening System for Steel Structures
This paper summarizes an experimental program supported by an analytical modeling study undertaken to investigate the bond behavior of carbon fiber reinforced polymer (CFRP) materials used for strengthening steel structures. The experimental program consisted of three double-lap shear coupon tests and five large-scale beam tests. Different methods to reduce the bond stress concentrations near the plate ends were investigated including increasing the length of the splice cover plate and implementing a reverse-tapere d plate end configuration. Three-dimensional linear and non-linear finite element analysis (FEA) was conducted to study the cracking behavior of the splice joints and to determine the effect of the reverse-taper on the interface shear and normal (peeling) stress distributions near the plate ends. The research findings indicate that implementation of the reverse taper at the plate ends can double the splice capacity as compared to conventional square plate ends. Based on the research findings simple design recommendations are presented to increase the ultimate capacity of splice joints. This paper demonstrates that splice joints can be effectively implemented to facilitate the use of CFRP strengthening systems for strengthening and repair of long-span steel beams.
Use of adhesives in repair of cracks in ship structures
AbstractThe structures of modern warships frequently contain significant quantities of aluminium alloy: a material especially prone to fatigue induced cracking. The satisfactory repair of such cracks is often vital if the fighting efficiency of a warship is to be maintained properly and would usually be carried out by welding. The welding of aluminium and its alloys is often difficult and onboard is further complicated by the necessity to remove inflammable linings, cables, and items of equipment to reduce the fire risk and provide access for the repair. Consequently, repair welds are often carried out from the most accessible side and are seldom full penetration. The finished weld is invariably little more than a sealant with a fatigue life inferior to that of the original plate. Initiation of further cracking in the repair weld can be prevented by adhesively bonding a reinforcement across the weld to provide a strength at least as good as that of the original plate and a stiffness sufficient to prevent ...