无粘结预应力GFRP管混凝土梁抗弯承载力计算  

Calculation Method of Flexural Capacity of Prestressed Composite Beams Using Concrete-Filled GFRP Tubes and Concrete Slabs with Unbonded Tendons

作　　者：秦国鹏[1] 王连广[1] 李宁[2] 

机构地区：[1]东北大学资源与土木工程学院,辽宁沈阳110004 [2]沈阳市房地产开发建设管理办公室,辽宁沈阳110013

出　　处：《沈阳建筑大学学报（自然科学版）》2009年第2期298-302,共5页Journal of Shenyang Jianzhu University：Natural Science

基　　金：国家自然科学基金项目(50208007);教育部博士点基金项目(20050145012);辽宁省重点实验室基金项目(JG-200601)

摘　　要：目的为了改善GFRP管混凝土梁的受力性能,增加刚度减小变形.方法考虑无粘结预应力GFRP管混凝土梁的受力特点,根据构件在不同状态下中和轴位置的不同,确定了4种破坏模式,利用平截面假定和应变变化计算方法,对构件抗弯承载力进行了分析.结果根据构件在极限状态下的受力特性,考虑中和轴分别位于混凝土板截面和GFRP管混凝土截面两种情况,确定了截面受压区高度,并建立了相应的抗弯极限承载力计算公式.结论将预应力技术运用到GFRP管混凝土结构中,让预应力筋代替普通钢筋来承担部分荷载,发挥其高强抗拉性能,通过施加预应力,又可以延缓受拉区混凝土过早的开裂,使构件的刚度得以提高,该方法是切实可行的;所建立的抗弯承载力计算公式形式简单,概念明确,便于实际应用.The design characteristics of concrete-filled GFRP tube composite beams can be improved by setting unbonded tendons to the critically stressed tension areas. Its failure is divided into four modes according to the different positions of neutral axis. Plane assumptions and strain variation in calculation are used when flexural strength of the components is analyzed. Considering the bearing capacity of composite beams, the corresponding formula for calculating capacity is introduced according to the different positions of neutral axis. The method is feasible which introduces prestressed composite beams using concrete-filled GFRP tubes and concrete slabs with unbonded tendons. The unbonded tendons have greater strength than normal ones. Also, the crack of concrete at tension sides can be restricted because of existence of prestressed forces. The equation is expressed clearly, simply and easily, which can be applied to provide a theoretical reference works.

关 键 词：无粘结筋 预应力 GFRP管混凝土 正截面承载力 计算公式 

分 类 号：TU398[建筑科学—结构工程]