反复荷载作用下纤维增强异形柱节点受力性能研究  

Study on mechanical behaviors of fiber reinforced joints with specially shaped columns under cyclic loading

作　　者：王铁成[1] 赵海龙[1] 张学辉[1] 郝贵强[1] 

机构地区：[1]天津大学建筑工程学院,天津300072

出　　处：《建筑结构学报》2010年第S2期226-231,共6页Journal of Building Structures

基　　金：国家自然科学基金项目(50878141)

摘　　要：由于异形柱柱肢薄弱,钢筋密集,受力复杂的节点是异形柱结构的薄弱部位。通过对两组节点核心区有无聚丙烯纤维增强的异形柱节点进行反复加载试验,对比分析每组异形柱节点的破坏特征及节点核心区应变规律,研究纤维增强异形柱节点薄弱部位的受力性能。研究表明:异形柱节点核心区截面不同位置箍筋应变和应力相差较大,节点腹板平行剪力方向箍筋拉力显著大于垂直剪力方向箍筋拉力和翼缘箍筋拉力,腹板箍筋屈服后翼缘箍筋拉力有大幅增长。纤维的加入可以提高混凝土主拉应变和抗拉强度,减小箍筋应变,使其变化平缓,改善节点处箍筋和混凝土应变分布进而推迟箍筋屈服。纤维增强后异形柱节点腹板开裂剥落现象改善,异形柱节点薄弱部位增强作用显著。As the thin leg and dense reinforcement in specially shaped columns,joints with complicated force are the weak parts of structure with specially shaped columns.Two groups of joints with specially shaped columns are tested under cyclic loading and comparison is made to analyze the failure characteristic and strain variation in the core area for joints with specially shaped columns with and without polypropylene fiber reinforcement in the core area in each group.Mechanical behavior of joints with specially shaped columns reinforced by polypropylene fiber to weak part is investigated in this paper.The results shown that the stress and strain in different sectional position in the core area of joints with specially shaped columns differs a lot and the tensile stress in stirrups in parallel to the direction of shearing force in web of joints is dramatically higher than that in perpendicular and that in the flange,also the tensile stress in the flange grows higher after the yield of stirrups in the web.The adoption of fiber can increase the tensile strain and tensile strength of concrete and decrease the tensile strain for stirrups in joints and make the variation of tensile strain in stirrups go smoothly,improve the strain distribution and delay the yield of stirrups.The state of concrete cracking and spalling in the web of joints with specially shaped columns is improved and the weak part of joints is reinforced by fiber significantly.

关 键 词：异形柱 聚丙烯纤维 反复荷载 

分 类 号：TU375.3[建筑科学—结构工程]