DESIGN OF FIBER REINFORCED POLYMERS (FRP) STRENGTHENED TIMBER BEAMS

摘要

The paper deals with the design procedure for strengthening timber beams using Fiber Reinforced Polymers (FRP). The main components of the paper are non-linear analysis and design guidelines. First, an analytical procedure was developed using a linear elastic behavior in tension and elasto-plastic behavior in compression for wood and linear elastic behavior for composites. A procedure was also developed to estimate the material properties needed for non-linear analysis from handbooks. The type of wood is the only parameter needed for the analysis. If other properties such as elastic modulus and modulus of rupture are known, they can be used in the analysis, instead of estimated properties. Delayed tension fracture of beams when FRP sheets are present in the tension face, are also accounted for in the analysis. The design guide lines consist of: estimation of FRP area required to resist the increased load and verification of the strength increase. A step by step procedure and a flow chart for the design are presented.