PVC-FRP管混凝土柱-钢筋混凝土梁节点受力性能及设计方法研究

This project takes RC beam to PVC-FRP confined concrete column joints as the research object, using the method of combining model test, numerical simulation with theoretical analysis, the connection mode of the core area of RC beam to PVC-FRP confined concrete column joints is studied, the reasonable construction measures of joint core area is determined, the calculation method of local compression bearing capacity of joint core area is put forward, and the equivalent uniaxial stress-strain model of joint core area is established. The bearing capability and failure mechanism of joint under static load is studied, the calculation method of bearing capacity and deformation of joint subjected to axial compression and eccentric compression is presented, and the relevant calculating theory of load-deformation of joint is established. The failure mode, stress mechanism and energy dissipation mechanism of joint under low cyclic loading is studied, the effect of various factors on dynamic characteristics and seismic performance of joint is analyzed, the calculation method of the flexural capacity, shear resistant bearing capacity, stiffness degradation and ductility coefficient of joint is proposed, and the restoring force model of joint is also established. The design method of joint is studied, the design principle, control target, control condition and specific structural measures of joint is put forward, and the design steps of joint design is also suggested. This research project will provide experimental and theoretical basis for the application of PVC-FRP confined concrete structure in the actual engineering, at the same time, it also has very important scientific significance to the development of structural engineering discipline.

本项目以PVC-FRP管混凝土柱-钢筋混凝土梁节点为研究对象，采用模型试验、数值模拟与理论分析相结合的方法，研究PVC-FRP管混凝土柱-钢筋混凝土梁节点核心区的连接方式，确定节点核心区连接的合理构造措施，提出节点核心区轴压承载力计算方法，建立节点核心区的等效单轴应力-应变关系模型。研究静力荷载作用下节点承载性能与破坏机理，提出轴压和偏压荷载作用下节点承载力和变形的计算方法，建立节点荷载-变形的相关计算理论。研究低周反复荷载作用下节点的破坏模式、传力机理和耗能机制，分析各因素对节点动力特性与抗震性能的影响规律，提出节点抗弯、抗剪承载力、刚度退化及延性系数的计算方法，建立节点恢复力模型。研究节点设计方法，提出节点设计原则、控制目标、控制条件和构造措施，建议节点的设计步骤。本项目研究将为PVC-FRP管混凝土结构在实际工程中的应用提供试验和理论依据，同时对结构工程学科的发展也有重要的科学意义。

本项目瞄准新型组合结构正在由构件层次向结构体系方向发展的趋势，立足工程应用，在前期PVC-FRP管钢筋混凝土柱抗震性能研究基础上，以PVC-FRP管混凝土柱-钢筋混凝土梁节点为研究对象，重点解决静力荷载和低周反复荷载作用下节点的破坏模式、受力机理、计算理论和设计方法等关键问题。（1）为便于PVC-FRP管混凝土柱和钢筋混凝土梁的连接，提出了环梁连接节点、钢筋网片连接节点、芯钢管连接节点三种节点连接方式，开展三种节点核心区轴压性能研究，分析节点截面、配筋率、配箍率、含钢率等因素对节点核心区的承载力、变形、裂缝、应力-应变关系的影响规律，揭示节点核心区破坏模式与受力机理。提出三种节点核心区轴压承载力和变形的计算方法，建立节点核心区的等效应力-应变关系模型，给出了节点核心区具体的连接方式和构造措施，验证节点连接形式的可行性。（2）开展PVC-FRP管混凝土柱-钢筋混凝土梁节点静力性能研究，分析环梁宽度、环梁高度、环梁配筋率、环梁配箍率、CFRP条带间距、偏心距等因素对节点承载力、变形、裂缝和荷载-位移相关曲线的影响规律，揭示静力荷载作用下节点破坏形态与受力机理。提出轴压和偏压荷载作用下节点承载力和变形的计算方法，建立节点荷载-位移的相关计算模型，优化节点连接构造措施。（3）开展PVC-FRP管混凝土柱-钢筋混凝土梁节点抗震性能研究，分析环梁宽度、环梁配筋率、轴压比、CFRP条带间距和钢筋混凝土梁的配筋率等因素对节点的承载力、应变、延性、滞回曲线、骨架曲线以及耗能能力的衰减规律，揭示低周反复荷载作用下节点破坏模式、传力机理与耗能机制。提出低周反复荷载作用下节点承载力、刚度退化和延性系数的计算方法，给出节点的骨架曲线和滞回规则，建立节点的恢复力模型。在此基础上，提出提出节点设计方法和连接构造措施。本项目的研究将为工业与民用建筑、桥梁结构和海洋结构等工程提供新的结构体系，为PVC-FRP管混凝土结构的设计以及在实际工程中的应用奠定基础。