GFWRP管增强混凝土柱的轴压泊松比
POISSON'S RATIO OF GFWRP TUBE REINFORCED CONCRETE UNDER AXIAL COMPRESSION
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摘要: 为完善和发展GFWRP管增强混凝土柱的设计与计算理论,设计并制备了不同管径、壁厚及缠绕角的GWFRP管混凝土柱试件。进行了轴心压缩试验并对试验结果回归分析,得到GFWRP管混凝土柱轴心压缩过程中转折点及峰值点的泊松比变化方程和相应的应变预测公式,得到组合结构轴压全过程的泊松比变化预测方程。可由给定的组分材料性能预测组合构件的极限泊松比和极限应变,达到预测实际工程中GFWRP管混凝土柱抗力与变形性能的目的。通过试验及计算结果对GFWRP管混凝土与传统钢管混凝土的泊松比变化趋势进行了对比分析,发现两者变化规律完全不同。进一步探讨了GFWRP约束管的纤维缠绕角对组合结构轴压泊松比的影响。结果表明,纤维缠绕角与轴压泊松比近似成反比关系。为制定合理的GFWRP复合材料增强混凝土柱规范提供了理论依据。Abstract: To develop the design and computational theory for GFWRP reinforced concrete structure, GFWRP reinforced concrete column specimens were designed and fabricated with different tube diameters, thicknesses and winding angles. The axial compression testing of the specimen was conducted, and its experimental results were analyzed based on the regression method. The equations describing the development of Poisson’s ratio and corresponding axial strain of GFWRP-concrete columns at the critical point and failure point were obtained. The equation to predict Poisson’s ratio development in the whole axial compression process was presented. So the peak Poisson’s ratio and corresponding axial strain of any GFWRP-concrete column can be forecasted in terms of the properties of its constituent materials, which can be used to predict the practical structural resistance and deformation capacity of the GFWRP-concrete column. According to the experimental and theoretical results, the Poisson’s ratio developments between GFWRP-concrete and traditional steel-concrete columns are quite different. The effect of the fiber winding angle of GFWRP tubes on the Poisson’s ratio of the combined structure under axial compression was analyzed. It reveals nearly inverse Poisson’s ratio dependences on the fiber winding angle. The results provide the theoretical basis for setting up the rational GFWRP-concrete structure standards.