矩形钢管高强混凝土上翼缘的工字形简支梁模态分析

MODAL ANALYSIS ON I-SHAPED SIMPLE-SUPPORTED BEAMS WITH RECTANGULAR HIGH-STRENGTH CONCRETE-FILLED STEEL TUBULAR UPPER FLANGE

为获得矩形钢管高强混凝土上翼缘的工字形简支组合梁的动力特性,文中采用ANSYS有限元软件,以腹板高度h_(2)和腹板厚度t_(w)为主要参数,对16根该类简支梁进行模态分析,获得简支梁的前5阶模态参数。采用集中质量法对简支梁的固有频率进行理论计算,并与有限元模拟结果进行对比,二者吻合较好。在此基础上重点考察了h_(2)和t_(w)对简支梁动力特性的影响,结果表明随着h_(2)的增加,简支梁的基频逐渐增加,而随着t_(w)的增加,简支梁的基频却逐渐减小,为进一步开展该类梁的抗震性能研究奠定基础。

To obtain the dynamic characteristic of the I-shaped beams with rectangular high-strength concretefilled steel tubular upper flange,taking the height and thickness of web-plate as the main parameters,a total of 16 simply-supported beams were designed to conduct modal analysis based on the ANSYS software.The first five-order modal parameters of the test beams were obtained,and the natural frequency of the test beam was calculated by mass concentration method,which agreed well with theoretical results.Furthermore,the influence regularity for height and thickness of web-plate on the dynamic characteristics of the simply-supported beams were mainly investigated.The results show that the first-order frequency of simply-supported beams increased with the increasing of h_(2),while the first-order frequency of this kind of beams decreased with the increasing of t_(w).The study may provide a reference for the seismic capacity of this kind of beams.