FRP加固木梁的受弯性能研究

为研究FRP板隐蔽式加固古建筑截面削弱型木梁的抗弯力学性能，设计了3组18根木梁试件的静力加载试验，比较了新构件替换残损构件与残损构件FRP板隐蔽式加固2种方式的加固效果，以及FRP板材的类型、厚度、加固长度对加固木梁抗弯性能的影响规律.研究结果表明：加固木梁抗弯极限承载力、抗弯刚度较模拟残损梁均显著提升；最优加固木梁的抗弯性能与健康梁相当.相同厚度的CFRP板加固木梁的抗弯性能优于GFRP板加固木梁；FRP板的厚度、加固长度与加固木梁的抗弯性能提高幅度成正比.在加固试件中木材、碳板胶以及FRP板的协同工作性能方面，GFRP板优于CFRP板.加固木梁截面应变沿梁截面高度方向的分布基本符合平截面假定.提出了FRP板加固木梁的抗弯极限承载力计算公式，计算结果与试验结果吻合较好.

Study on flexural behavior of timber beams strengthened with FRP

To study the bending behaviors of ancient building timber beams strengthened with near-surface mounted FRP sheets, three groups of eighteen specimens under static loading tests were designed. The reinforcement effects of two ways of replacing damaged members with new ones and with NSM FRP reinforcement were compared. The effects of different types, thicknesses, and lengths of FRP sheets on the bending performance of timber beams were analyzed. The research results show that the ultimate bearing capacity and flexural rigidity of strengthened beams are much higher than that of the unstrengthened simulated damaged ones. Compared with the intact beams, the bending behaviors of optimal strengthened ones are equivalent to that of the intact ones. The bending mechanical properties of bending plate with the same thickness of the CFRP sheets strengthened beams are superior to that of the GFRP sheets strengthened beams. With the FRP sheets thickness, reinforcement length increases, the flexural performance of the strengthened beams can be significantly improved. For the reinforced beams, GFRP sheets outperformed CFRP sheets in terms of concerted performance of the timber, the carbon plate glue and the fiber panel. The strain distribution of reinforced beams along the section height direction of the beam conforms to the plane section assumption on the whole. A calculation model for predicting ultimate moment capacity of pine timber beams strengthened with FRP was put forward, and the calculated results agree well with the observed data.