预应力 FRP筋混凝土梁正截面受弯承载力计算方法研究

摘要

为研究预应力 FRP配筋混凝土梁正截面受弯承载力计算方法，以完全非金属试验桥-秭归松树坳大桥为依托工程，提出基于平截面假定的预应力 FRP筋梁正截面承载力的理论计算方法。利用该理论计算了完全非金属20 m预应力空心板梁的正截面受弯极限承载力，用有限元数值计算的结果验证了其准确性。FRP 筋材的应力-应变为完全线性，其承载能力的计算方式与普通混凝土构件有所不同。完全非金属梁进行超筋设计，以构件受压区混凝土压碎为破坏依据是合理的，此时的 FRP筋材应未达到设计强度，而且利用积分代替等效矩形应力图形简化的计算方式可得到更准确的结果。%In order to study the calculation methods for normal section flexural bearing capacity of pre-stressed FRP tendon concrete beam,as the basis for a test bridge “Zigui Songshuao bridge project”which was completely made use of non-metallic materials,the paper presented a theoretical calculation methods for normal section flexural bearing capacity of prestressed FRP tendon concrete beam that is based on plane section assumption.Using this method calculated the normal section flexural bearing ca-pacity of completely non-metallic 20 m prestressed FRP tendon concrete hollow beam in Zigui Songshuao bridge project,and verified its accuracy by using the finite element calculation results.Because the stress and strain of FRP reinforcement is completely linear change,its calculation for flexural bearing capacity is completely different with ordinary concrete structures.In the course of calculating normal section flexural capacity of FRP reinforced beam,it designed by over bars method,and its basis for structural failure was concrete crushing in the compression zone.The FRP reinforcement at this time did not meet the design strength.Using the integral method instead of the calculation method for equivalent rectangular stress graph simplified can get more accurate results.