梯级GFRP筋混凝土受弯构件多塑性区形成机制  

Formation mechanism of multi-plastic regions in concrete flexural members with graded GFRP bars

作　　者：邓江东[1] 杨思远 郭春泉 DENG Jiangdong;YANG Siyuan;GUO Chunquan(Civil Engineering School,Guangzhou University,Guangzhou 510006,China)

机构地区：[1]广州大学土木工程学院,广州510006

出　　处：《复合材料学报》2023年第11期6324-6335,共12页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(51978183)。

摘　　要：为提高混凝土受弯构件的抗震性能,采用玻璃纤维增强树脂复合材料(Glass fiber reinforced plastic,GFRP)筋和钢筋梯级配置的方案,构建同外力分布相适配的承载能力梯级分布,以形成多塑性区。本文设计了5个具有不同梯级配筋参数的混凝土受弯试件,对比参数包括梯级高度、配筋种类、配筋量和配筋方式等,通过推覆(Pushover)试验对比分析各试件中多塑性区的产生情况和力学效果,研究多塑性区的形成机制。结果表明:合理的梯级配筋方案可以在混凝土受弯构件中形成多个塑性区,塑性区的个数和发展程度会显著影响构件的抗震行为。多塑性区形成的决定条件是构件中多个梯级段所受外弯矩介于其屈服弯矩与极限弯矩之间。通过调整梯级段长度与配筋参数,可有效地调控各塑性区的发展程度及构件的破坏位置和破坏模式。线弹性的GFRP筋为截面提供了较大的抗弯承载力屈服后增量,是多塑性区形成和调控的关键。In order to enhance the seismic capacity of concrete flexural members,a graded reinforcement scheme with the glass fiber reinforced plastic(GFRP)bars and the steel bars was developed to make a graded distribution of bearing capacity that matches the external force distribution,and then multiple-plastic regions were formed.Five concrete flexural members with different graded reinforcement parameters were designed,and the comparison parameters included the height of the grades,the type of bars,the reinforcement ratios and the construction methods.Through the pushover experiment,the formation and mechanical effects of multi-plastic regions were studied,and the formation mechanism of multi-plastic regions was analyzed in details.The results show that the reasonable graded reinforcement scheme can form multi-plastic regions in the concrete flexural member.The number and development degree of plastic regions significantly affect the seismic behaviours of members.The formation condition of the multi-plastic regions is that the external moment is between the sectional yield moment and ultimate moment in several grades.The development level of each plastic region can be effectively controlled by adjusting the length and reinforcement of the grades,and the failure position and failure mode of the member can be designed.A great increment provided by GFRP bars with line elasticity properties on the bending bearing capacity after yielding is a key factor for the formation and regulation of multi-plastic regions.

关 键 词：混凝土受弯构件 多塑性区 梯级配筋 形成机制 抗震行为 GFRP筋 

分 类 号：TU375.1[建筑科学—结构工程] TB332[一般工业技术—材料科学与工程]