圆形纤维增强塑料缠绕混凝土柱在持续轴向压缩下的面向设计的模型分析（英文）

Design-oriented modeling of circular FRP-wrapped concrete columns after sustained axial compression

目的:在实际工程服役过程中,纤维增强塑料(FRP)约束混凝土柱在遭遇极限荷载前往往已经经历了长时间的轴压荷载作用。因此,相比其短期力学性能,本文旨在研究FPR约束混凝土柱在长期荷载作用后的力学性能。创新点:1.考虑长期轴压荷载作用,提出一种轴压作用下圆形截面FRP约束混凝土柱的长期变形分析模型;2.提出了长期轴压作用后的FRP约束混凝土本构模型,从本构关系的角度描述两个方面的影响机理。方法:运用混凝土和FRP徐变的长期变形分析迭代计算方法(图3)。结论:1.提出的长期变形分析模型实现了对FRP约束混凝土柱任意目标时刻的应力和应变状态的高效、准确预测;2.将提出的本构模型嵌入有限元软件中,有效地实现对长期轴压作用的考虑;3.基于Open Sees有限元软件,验证了长期变形分析模型和本构模型的有效性和准确性。

Fiber-reinforced plastic-wrapped concrete columns （FRP-C） have been extensively used in building structures and transportation infrastructures around the world during the past two decades. These members are actually subjected to a long-term sustained axial compression before they experience the designated ultimate loading. However, little attention has been given to the performance of FRP-C after sustained axial compression compared with that of its short-term instant performance. This study aims to establish a design-oriented numerical model for the long-term deformation of circular FRP-C after sustained load. A modifi ed constitutive model of FRP-wrapped concrete is proposed for numerical analysis of FRP-C considering two dominant effects of sustained axially compressive loading. Numerical verifi cations against existing tests indicates that the ultimate strength will be slightly enhanced while the ultimate strain will be conspicuously reduced in most cases of normal strength FRP-C after a long-term sustained load.