钢筋混凝土组合梁的损伤诊断实验研究  

Experimental study on damage diagnosis of RC composite beam

作　　者：霍兵勇[1,2] 易伟建[1] 胡岚[1] 马克俭[1] 

机构地区：[1]湖南大学土木工程学院,长沙410082 [2]许昌学院土木工程学院,许昌461000

出　　处：《中国科学：技术科学》2015年第7期757-765,共9页Scientia Sinica(Technologica)

摘　　要：为探寻不同状态下U形钢板-混凝土组合梁的动力性能及其在结构状态评估中的应用,本文对3根组合梁进行了分级均布静力加卸载试验,期间卸掉荷载后,进行脉冲锤击激励条件下的动力测试,采用模态分析软件Mescope对测试中记录的传递函数(TRF)进行计算得到模态参数,总结了组合梁的动力性能特点,舍去了振型在支座位置幅度较大的重复模态,选择相对稳定的模态参数作为评估依据,组合梁中钢和混凝土的粘结作用较强时,频率较高而阻尼系数较小,相反粘结作用较弱时,频率较低而阻尼系数较大.结果表明:模态参数有一定的离散性,频率和阻尼比随构件状态变化规律比较明显,可作为结构损伤指标,相对稳定的模态振型随构件状态的变化极其微小,对结构损伤指示作用不大,可用来判断真假模态.For finding out dynamic characteristics of U-shaped steel plate-concrete composite beam in difference state and application in structural condition assessment, the experience of static multi-stage loaded and unloaded were performed on three composite beams by uniformly distributed weights. After unloading dynamic test were carried out with pulse excitation. Then the recorded transfer function was calculated by modal software Mescope to obtain the modal parameters. Dynamic characteristics of the composite beam had been summed up. Repeated modal were given up of which the magnitude is bigger at the supports, meanwhile the steady modal parameters were taken on an evaluation basis. While the bond action of steel bar/plate and concrete in composite structures were stronger, the frequencies were higher and the values of damp ratio were smaller. Whereas： if the bond action was weak, the frequencies will become smaller and the values of damp ratio higher. The results indicated that modal parameters were dispersed at some level, but the changes of frequency and damp ratio with damage may serve as a structural damage indicators, the stable modal shapes was influenced slightly by damage, which can be used to determine true and false mode and would not be used to indicate structural damage.

关 键 词：U形钢板-混凝土组合梁 动力性能测试 模态分析 重复模态 损伤诊断 

分 类 号：TU375.1[建筑科学—结构工程] TU317