混凝土局部楼盖模态测试及FEM模拟分析

Modal test and finite element simulation of concrete local floor

为研究局部楼盖动力特性,本文以某小学体育馆框架结构体系为工程背景,采用环境激励对一层局部楼盖进行了模态测试。通过合理布置测点,采用单点拾振准确获取各测点振动加速度,并利用自互功率谱方法进行模态识别,得到局部楼板实测动力特性。采用有限元法进行模拟分析,结果表明:所得有限元分析结果与现场实测结果前两阶振型图基本一致,振动频率偏差值仅为3.7%和5.9%,本文测试方法与模拟方法可以有效掌握结构局部楼盖动力特性,从而为动力测试和有限元模拟提供参考和依据。

In order to study the dynamic characteristics of the local floor,the frame structure of the gymnasium of a primary school was used as the engineering background and a modal test was conducted on the local floor using the environmental excitation.By arranging the measurement points reasonably,the vibration acceleration at each measuring point was obtained accurately using the single-point vibration pickup method.The modal identification was carried out using the self-reciprocal power spectrum method in order to obtain the measured dynamic characteristics of the local floor.Then,the finite element method(FEM)was used in order to simulate the structural dynamic characteristics of the local floor.The results were basically consistent with the first two modes of field measurement.The deviation of the vibration frequency was only 3.7%and 5.9%.The test and simulation methods used in this study can capture the dynamic characteristics of the structure′s local floor in a better way,and thus provide the reference and basis for dynamic tests and FEM simulations.