高延性大应变FRP-混凝土-高强钢实心柱轴压力学性能研究

A novel large rupture strain FRP-concrete-HSS tube solid column form is proposed in the current project to address the following two issues: (1) For a concrete encased HSS column, the concrete and the HSS are not compatable in terms of ultimate deformation capacity; (2) the HSS steel tube would easily experience buckling failure for concrete-filled HSS tube columns or FRP-concrete-steel double-skin tubular columns. The proposed new column form enables fully utilization of capacities of the three components in the hybrid solid column, possesses excellent deformability, and envolves environmentally friendly FRP composites. This research project aims to clarify the work mechanism of the proposed hybrid solid columns and the interaction between FRP tube, concrete and steel according to monotonic and cyclic axial compression tests and numerical investigations on large rupture strain FRP-concrete-HSS tube hybrid solid columns, in material, basic column and hybrid column levels. Meanwhile, the effects of yield strength of steel, confining stiffness of FRP, inner and outer tube diameter ratio and shape of column section, etc. on mechanical properties of hybrid solid columns and stress-strain behavior of confined concrete are investigated based on a large amount of parametric studies. Research outcomes will enable new theoretical models for load carrying capacity and deformation of FRP-concrete-HSS steel hybrid solid columns, and facilitate design and applications as scientific basis.

本项目提出高延性大应变FRP-混凝土-高强钢实心柱构件，拟同时解决以下两个问题：（1）高强型钢混凝土组合柱中钢材与混凝土两种材料极限变形能力不匹配问题；（2）高强钢管混凝土或者FRP-混凝土-钢双壁空心柱钢管屈曲的问题。该新型构件可以充分发挥三种材料的承载能力，抵抗变形能力优异，且采用环境友好型大应变FRP。本项目将进行大应变FRP-混凝土-高强钢实心柱单调轴压与往复轴压试验研究和数值模拟，从材料、基本构件和组合构件三个层次探究该新型组合实心柱受力机理、各组分相互作用机理。同时，通过广泛的参数分析探明钢管强度、FRP约束刚度、双管直径比、截面形状等参数对组合实心柱轴压力学性能与其中约束混凝土本构关系的影响。试验与数值模拟结果将用于提出FRP-混凝土-高强钢实心柱的承载力、变形理论模型，为其设计及应用提供科学依据。

本项目提出高延性大应变FRP-混凝土-高强钢实心柱构件，拟同时解决以下两个问题：（1）高强型钢混凝土组合柱中钢材与混凝土两种材料极限变形能力不匹配问题；（2）高强钢管混凝土或者FRP-混凝土-钢双壁空心柱钢管屈曲的问题。本项目进行大应变FRP-混凝土-高强钢实心柱单调轴压、往复轴压与偏压试验研究，从材料、基本构件和组合构件三个层次探究该新型组合实心柱受力机理、各组分相互作用机理。研究结果证实了同时，开展了广泛的参数分析，探明了钢管强度、FRP约束刚度、双管直径比、截面形状等参数对组合实心柱轴压力学性能与其中约束混凝土本构关系的影响。基于研究结果，提出了FRP-混凝土-高强钢实心柱的承载力、变形理论模型，为其设计及应用提供了科学依据。