摘要
以深圳市试验学校运动场为背景,采用有限元模拟研究了40m跨度组合梁楼盖在人群跳跃、人群跑步激励下的振动舒适度情况,得到了楼盖的基本频率、模态和加速度时程响应。将结果与规范的限值进行了对比,并对影响组合梁楼盖振动舒适度的参数进行了分析,结果表明:40m组合梁楼盖的基本频率为4.43Hz,二阶频率为5.31Hz,楼盖在有节奏人群激励工况1、工况2下的加速度峰值分别为245.1mm/s^(2)、439.6mm/s^(2),均满足AISC#11和JGJ/T-441的限值要求。通过参数分析发现:随着人致荷载频率f_(1)逐渐靠近楼盖自振频率,加速度峰值总体呈增大趋势,且在f_(1)和f_(1)/2处明显增大。相较于铰接,楼盖与钢梁边界为刚接时,楼盖的自振频率增加8.9%,加速度峰值减小14.2%。对组合梁的钢梁高度和楼盖厚度进行分析,发现通过改变梁截面尺寸以达到控制楼盖体系基本频率更为合理,改变梁截面尺寸和楼盖厚度均能达到控制加速度响应的效果。
Taking sports field of Shenzhen Experimental School as background,the vibration comfort of 40m span composite beam floor excited by crowd jumping and crowd running was studied by finite element simulation.The basic frequency,mode and acceleration time history response of the floor were obtained.The results were compared with the limit values of the specifications.The parameters affecting the vibration comfort of the composite beam floor were analyzed.The results showed that the basic frequency of the 40m composite beam floor was 4.43Hz,the second-order frequency was 5.31Hz.The acceleration peaks of the floor under the rhythmic crowd excitation condition 1 and 2 were 245.1mm/s^(2) and 439.6mm/s^(2) respectively,which meet the limit requirements of AISC#11 and JGJ/T-441.Through parameter analysis,it was found that as the human induced load frequency f_(1) gradually approached the natural vibration frequency of the floor,the peak acceleration generally increased,and increased significantly at f1and f_(1)/2.Compared with hinged connection,When the boundary of floor and steel beam was rigid connection,the natural vibration frequency of floor increased by 8.9%and the peak acceleration decreased by 14.2%;Through the analysis of the steel beam height and floor thickness of the composite beam,it was found that for the long-span floor system,it was more reasonable to control the basic frequency of the floor system by changing the beam section size.The acceleration response can be controlled by changing the beam section size and floor thickness.
作者
芦静夫
郑星
黎钟文
LU Jingfu;ZHENG Xing;LI Zhongwen(China Construction Science&Technology Group Co.,Ltd.,Shenzhen 518118,China)
出处
《建筑结构》
CSCD
北大核心
2022年第S02期533-538,共6页
Building Structure
基金
中国建筑股份有限公司科技创新平台(CSCEC-PT-005)
中建科技集团有限公司科技研发计划(ZJKJ-2021-2)
关键词
大跨度楼盖
组合梁
振动特性
加速度
参数分析
long-span floor
composite beam
vibration characteristics
acceleration
parameter analysis
