考虑流固耦合影响的水中桩基结构振动特性分析  

Vibration characteristics analysis for underwater pile foundation structure considering fluid-structure interation

作　　者：王元战[1] 王朝阳[1] 

机构地区：[1]天津大学建筑工程学院 天津市港口与海洋工程重点实验室,天津300072

出　　处：《水道港口》2013年第1期73-79,共7页Journal of Waterway and Harbor

基　　金：国家自然科学基金项目(51279128)资助;天津市科技支撑计划重点项目(10JCYBJC03400);天津市自然科学基金项目(10SYSYJC27300)

摘　　要：水-结构的耦合振动是一个比较复杂的问题,在设计中,只有考虑水体对结构基频及阻尼比等振动特性的影响,才能使结构设计更为合理、可靠。以往研究多分析水体的附加质量效应对桩柱基频的影响,对水深、桩径、上部结构等因素的影响尚缺乏进一步的研究,对水体的阻尼比增大效应也缺乏定量分析。鉴于工程的需要,利用有限元分析软件ADINA建立水体-桩基结构相互作用的三维有限元数值模型,对流固耦合作用下结构的基频和阻尼比进行计算,分析多种因素对水中结构振动特性的影响,并给出水体产生的阻尼比推荐值。结果表明,水体会引起结构基频降低及结构阻尼比增大,流固耦合作用对振动特性的影响不容忽视。The coupled vibration of water and structure is a complicated problem. In order to make the structural design more reasonable and reliable, the water influence on the basic frequency and damping ratio of the pile foundation structure should be considered. Most of the previous researches focus on the added mass effect of water on the basic frequency, while the impact of water depth, pile diameter, the superstructure and other factors are not considered, and the increase of damping ratio caused by water is lack of quantitative analysis. A 3-D finite element model of pile foundation structure considering fluid-structure interaction was established with ADINA in order to calculate the structure vibration characteristics analysis and damping ratio considered the fluid-structure interation effect. Then various factors influence on the vibration characteristic of structure in water were analyzed by this model, and the recommended value of damping ratio caused by water was given. The results show that water body can cause decrease of the basic frequency and increase of damping ratio,and the effect of FSI on the vibration characteristics of the structure can not be ignored.

关 键 词：桩基结构 水体 流固耦合 基频 阻尼比 

分 类 号：U655.544.1[交通运输工程—港口、海岸及近海工程]