FRP约束圆形和矩形截面混凝土柱应力-应变关系统一计算模型

Unified model for calculating stress-strain relationship of circular and rectangular concrete columns confined with FRP

将FRP约束混凝土柱应力-应变关系曲线以转折点为界分为两段,根据曲线的边界条件分别确定这两段曲线模型的计算公式,通过对FRP约束混凝土在平面应变条件下的力学分析,并考虑截面有效约束的影响,推导出转折点应力、应变的计算公式,通过对已有模型的分析比较和对试验数据的回归分析得出极限应力模型,根据能量平衡推导出极限应变的计算表达式,最终得到FRP约束圆形和矩形截面混凝土柱应力-应变关系统一计算模型.计算结果与试验数据的对比表明,根据本文模型计算的曲线与试验所得曲线吻合较好.

Stress-strain relationship curves of concrete columns confined with FRP were divided into two sections by transitional points.Each was determined according to the curve boundary conditions respectively.The stress and strain of transitional point were determined through mechanical analysis in plane strain conditions.The effectiveness of confinement by cross-section was considered.The ultimate stress was determined through comparison with existing models and regression analysis of experimental results.The ultimate strain was determined according to the energy balance criterion.A unified model for calculating stress-strain relationship of circular and rectangular concrete columns confined with FRP was proposed.The comparison shows that theoretical results are in good agreement with experimental results.