钢梁外包FRP混凝土抗弯承载力计算

Calculation of Flexural Capacity of Steel Beams Strengthened with Enclosed Reinforced FRP Concrete

目的研究一种简化处理的不同破坏形态下构件极限抗弯承载力的计算方法,以方便工程实际的应用.方法采用实用叠加方法对SRHC梁贴FRP的受力过程和破坏特征进行研究.根据中和轴到钢骨的截面距离不同,将受压区高度与钢骨上翼缘至混凝土受压边缘的距离进行比较,以此来确定FRP加固后梁在破坏时的不同抗弯承载力的适用公式.基于纤维模型法,对受弯钢梁外包混凝土贴FRP布构件进行非线性全过程分析.结果提出了受弯钢梁外包混凝土贴FRP布构件承载力计算公式.通过实例表明,FRP的加固层数是构件受力性能重要的影响参数,在相同的变形条件下,FRP层厚度增加,组合构件的承载能力也有所提高,最佳加固率在3层以内.构件的承载能力随着混凝土强度的提高而提高.结论笔者给出的计算公式克服了简单叠加法和一般叠加法在计算上的缺陷,计算简便,可用于工程实际和结构设计中.

The paper aims to put forward the calculation formula of flexural bearing capacity of steel beams strengthened w ith enclosed reinforced concrete boned FRP（ Fiber Reinforced Poiymer） under the different failure modes. In this paper,the load-deformation process,flexural failure characteristics of SRHC beams strengthened w ith FRP w ere researched by a new practical superposition method. A corresponding calculation method of flexural capacity according to the different positions of central axis and section of steel and the compressive region height under three medols of destroy is put forw ard. Based on the fiber model method, the w hole process for nonlinear analysis of flexural capacity of SRHC beams strengthened w ith FRP is analyzed. The paper puts forw ard the reasonable calculation formulas and the flexural capacity is improved w ith the increase of concrete strength. The FRP fabric content is one of the important parameters,and flexural capacity is improved w ith the increase of FRP w ithin three layers. The calculation formula of flexural bearing capacity of flexural members,further improves the accuracy and reasonability for calculating the bearing capacity of normal section for SRHC beams strengthened w ith FRP. The w hole process of steel beams strength-ened w ith enclosed reinforced concrete boned FRP is given a effective means,w hich is convenient for the actual combined members in engineering application.