摘要
以某近海导管架式海上风机结构为背景,基于ANSYS有限元软件分析不同桩土效应模拟方法对导管架式海上风机结构动力特性的影响,包括直接固结法、等效嵌固法、六弹簧法、m法、P-y曲线法、t-z曲线法和Q-z曲线法。结果表明:利用m法和P-y曲线法模拟水平向桩-土相互作用时对应的结构低阶频率十分吻合,起到互相验证的作用,而采用直接固结模型忽略桩土效应的影响会较大幅度地高估结构自振频率;采用3倍桩径等效嵌固模型以及六弹簧法模型均高估了结构自振频率,且六弹簧法在等效弹簧刚度计算方面较为繁琐。考虑有限元模拟的便利性,建议采用m法进行结构动力特性模拟。此外,对于摩擦桩,竖向桩土效应会较大幅度降低结构基频,因此需结合t-z曲线法和Q-z曲线法考虑竖向桩土相互作用对结构自振特性的影响。
Based on a jacket offshore wind turbine structure,the influence of different pile-soil effect simulation methods on the dynamic characteristics of the jacket offshore wind turbine structure was analyzed by ANSYS finite element software,including direct embedded method,equivalent embedded method,six-spring method,m method,P-y curve method,t-z curve method and Q-z curve method.The results show that the low-order modal frequencies of the structures using the m method and the P-y curve method for simulation of the horizontal pile-soil effects are very consistent with each other,which plays a role of mutual verification.The fundamental frequency of the structure will be greatly overestimated if the pile-soil effect is ignored in the directly embedded model.The 3 times of pile diameter equivalent embedded model and the model based on the six-spring method both overestimate the fundamental frequency of the structure,and the six-spring method is complicated in the calculation of equivalent spring stiffness.Considering the convenience in finite element simulation,it is suggested to adopt the m method to simulate the dynamic characteristics of the jacket offshore wind turbine structure.In addition,for friction piles,the vertical pile-soil interaction may greatly reduce the fundamental frequency of the structure,thus the t-z curve and Q-z curve related to the vertical pile-soil interaction effect should be taken into account during the analysis of structural dynamic characteristics.
作者
王浩然
马婷婷
蔡玮镇
WANG Haoran;MA Tingting;CAI Weizhen(College of Ocean Science and Engineering,Shanghai Maritime University,Shanghai 201306,China)
出处
《建筑结构》
CSCD
北大核心
2022年第S01期2468-2473,共6页
Building Structure
基金
国家自然科学基金青年基金项目(52008240)
上海市“全渗透”深远海离岸能源动力前沿科学研究基地(培养)
关键词
海上风机
导管架
动力特性
桩土效应
有限元模拟
offshore wind turbine
jacket
dynamic characteristic
pile-soil effect
finite element simulation
