疲劳荷载作用下梁内不同类型钢筋破坏关系  

The failure relationship between different types of steel in beams under fatigue loading

作　　者：宋玉普[1] 韩基刚[1] 

机构地区：[1]大连理工大学建设工程学部,辽宁大连116024

出　　处：《哈尔滨工业大学学报》2012年第8期96-100,共5页Journal of Harbin Institute of Technology

基　　金：国家高技术研究发展计划项目(2007AA11Z133);辽宁省教育厅科技计划项目(2008T231)

摘　　要：为了研究在疲劳荷载作用下,梁内钢筋的应力变化情况,通过12片后张有粘结部分预应力混凝土梁的疲劳试验,研究了与疲劳破坏密切相关的钢筋最大应力、应力幅的变化规律.结果表明:在梁的使用阶段,预应力钢筋与非预应力钢筋的应力幅比值处于等比例变化,非预应力钢筋应力幅是影响部分预应力混凝土梁疲劳性能的关键因素.随着重复荷载次数的增加,钢筋与混凝土之间粘结性能的退化和有效预应力的不断降低是两种不同类型钢筋破坏并不同步的两个重要原因.最后,在试验分析的基础上,提出了开裂截面处消压后预应力钢筋应力增量的计算公式,计算结果与试验结果吻合较好.To investigate the stress variation of reinforcement in beam under fatigue loads,in this paper,based on fatigue test results of 12 post-tensioned partially prestressed concrete beams,the changes of reinforced maximum,stress amplitude which are closely related with the fatigue failure of partially prestressed concrete beams are obtained.The experimental results suggest that the prestressed and non-prestressed reinforced are basically at the same ratio of development.It has been found that the key factors of affecting fatigue capability of partially prestressed concrete beams are stress amplitude of reinforcement.The bond degradation of reinforcement and reduction of effective prestressed stress lead to stress redistribution,which are the two main important reasons why prestressed and non-prestressed reinforced damages are not in desynchronized way with the increase of repeated loading.Finally,a calculation method of prestressed steel stress increment in a cracked section after decompression is proposed by the experimental analysis,and the calculation results are matched with the test results quite well.

关 键 词：部分预应力混凝土梁 疲劳 钢筋应力 粘结退化 应力重分布 

分 类 号：TH133[机械工程—机械制造及自动化] TP183[自动化与计算机技术—控制理论与控制工程]