钢筋锈蚀对RC固端梁振动特性的影响  

Effect of Reinforcement Corrosion on Vibration Characteristics of Fixed-End RC Beams

作　　者：徐略勤[1,2] 陈叙先 周建庭[2] 王佩 高鹏 阳珊清 XU Lueqin;CHEN Xuxian;ZHOU Jianting;WANG Pei;GAO Peng;YANG Shanqing(School of Civil Engineering,Chongqing Jiaotong University Chongqing,400074,China;State Key Laboratory of Mountain Bridge and Tunnel Engineering,Chongqing Jiaotong University Chongqing,400074,China)

机构地区：[1]重庆交通大学土木工程学院,重庆400074 [2]重庆交通大学省部共建山区桥梁及隧道工程国家重点实验室,重庆400074

出　　处：《振动．测试与诊断》2023年第5期967-973,1041,共8页Journal of Vibration,Measurement & Diagnosis

基　　金：国家重点研发计划资助项目(2018YFB1600300,2018YFB1600301);重庆英才计划资助项目(cstc2022ycjh-bgzxm0133);重庆市教委科学技术研究资助项目(KJQN201900737);研究生科研创新资助项目(2021S0020)。

摘　　要：为了揭示钢筋锈蚀对钢筋混凝土(reinforced concrete,简称RC)固端梁振动特性的影响,制作了纵筋直径分别为14 mm和16 mm的2组梁S‑14和S‑16,每组4片,一共8片。以0%,5%,10%和15%为目标锈蚀率对2组梁开展电化学加速锈蚀试验,基于受迫振动法测试了2组梁的振动特性,分析了交流电和环境振动两个干扰因素对测试准确性的影响,研究了纵筋锈蚀率、直径对RC固端梁振动特性的影响规律,探讨了荷载、截面刚度与频率之间的关联。结果表明:干扰因素对固端梁频率的影响可忽略,但对阻尼比有一定的影响,尤其是环境振动最大可产生43.62%的偏差;随着纵筋锈蚀率的增大,固端梁的频率不断下降,S‑14和S‑16梁的最大降幅分别达16.89%和8.13%,且纵筋直径越小,频率的降幅和降速越大;2组梁的阻尼比随纵筋锈蚀率的变化规律不一样,从测试结果的可重复性、稳定性和规律性来看,频率均优于阻尼比;随着锈蚀率的增大,固端梁荷载和频率表现出类似的下降规律,两者表现出良好的指数关系,固端梁截面刚度的变化率是其振动频率变化率的2倍。To reveal the influence of steel corrosion on the vibration characteristics of fixed-end reinforced concrete(RC)beams,two groups of RC beams(named S-14 and S-16)with longitudinal reinforcement diameters of 14 mm and 16 mm were respectively fabricated.The two groups are consisted of 8 beams in total with 4 beams in each group.The electrochemically accelerated corrosion method is applied to each group with the target corrosion rates of 0%,5%,10%and 15%set for the four beams respectively.Forced vibration tests are then carried out to obtain the vibration characteristics of the 8 beams.Based on the test results,the effects of alternating current and environmental vibration are analyzed on the accuracy of tests,and the influences of corrosion rate and longitudinal reinforcement diameter are studied on the vibration characteristics of RC fixed-end beams.Finally,the relationships between load and frequency,section stiffness and frequency are discussed.The research showes that the interference factors has a negligible effect on the vibration frequency of fixed end beams,but has a certain influence on the damping ratio where the maximum deviation can be 43.62%when subjected to a vibrational environment.As the corrosion rate of longitudinal reinforcement increases,the frequency of fixed-end beam decreases continuously,with the maximum reductions being 16.89%and 8.13%respectively for the groups of S-14 and S-16.The decreasing amount and rate of the vibration frequency become larger when the longitudinal reinforcement diameter is smaller.The damping ratio of beam in the two groups varies in different patterns with the corrosion rate of longitudinal reinforcement.Both theoretical and measured results show that the change rate of fixed-end beam section stiffness due to the steel corrosion is twice that of vibration frequency.

关 键 词：RC固端梁 振动特性 受迫振动法 钢筋锈蚀 纵筋直径 截面刚度 

分 类 号：TU375.1[建筑科学—结构工程]