碳纤维布加固箱梁桥正截面强度的计算

A Study on the Calculation Method of the Normal Section Strength of the RC Box Girder Strengthened With Carbon Fiber Sheets

针对碳纤维布加固箱梁正截面承载力的问题,开展非线性有限元全过程仿真分析.利用ANSYS及其二次开发技术,建立考虑材料、几何双重非线性的有限元模型,模拟箱梁受力的非线性全过程,计算结果与《公桥规》方法对比,证明有限元方法的可靠性.在此基础上,开展不同预应力度模型的有限元模拟计算,得出碳纤维布加固箱梁的受力特点、破坏模式以及正截面破坏时混凝土、预应力钢筋、碳纤维布的应力情况。根据分析模型的破坏特点,本文提出计算假设,建立碳纤维布加固箱梁正截面承载力的实用计算公式,为碳纤维布加固箱梁正截面承载力计算提供了可靠的方法。

Aiming at the bearing capacity of the normal section of the RC box girder strengthened with CFS, this thesis carries out its non-linear finite element overall process simulation analysis. By using redeveloped ANSYS, the thesis builds the finite element analysis model considering both material and geometry nonlinearity to simulate the nonlinear overall process of the box girder with CFS and proves the reliability of FEM by comparing the calculation results with those based on ＂The General Code of the Design of Highway Bridges and Culverts＂. On this basis, finite element simulation calculations of different pre-stressed degree models are carried out to get their mechanics features and failure modes of the box girders strengthened with CFS, and the stress states of concrete, pre-stressed reinforcement and CFS when the normal section is destroyed. According to the destruction features of the analysis models, the thesis proposes a set of practical and reliable calculation methods and formulae of the bearing capacity of the normal section of the box girder strengthened with CFS, which can be widely used in the design of the RC box girder bridge strengthened with CFS.