塔顶排架结构对进水塔动力响应的影响
The Influence of Top Bent Structure on Dynamic Response of Intake Tower
杨子照 1张继勋 1任旭华 1陈旻铭1
作者信息
- 1. 河海大学水利水电学院,江苏 南京 210098
- 折叠
摘要
进水塔顶部启闭机室通常为排架结构,地震时往往先发生损坏导致水电站无法正常运行.为探索塔顶排架结构对进水塔动力响应的影响,针对某抽水蓄能电站下水库的进水口结构动力响应开展研究.基于双自由度无阻尼简化体系进行理论探索,并采用三维非线性有限元数值模拟方法计算进水塔有、无塔顶排架两种工况的自振特性、位移、加速度、应力、损伤体积比和能量耗散等指标来对比研究.任意时刻的地震反应用时程分析法求解,并引入黏弹性人工边界模拟地基辐射阻尼作用.结果表明,地震时进水塔—排架系统可能会产生鞭梢效应进而减小进水塔的动力响应.塔顶排架使进水塔的自振频率提高约 2.10%～3.80%,使塔体关键点最大相对位移的最大值及最大加速度的最大值减小,减幅分别大于 23.94%、22.30%.有排架时进水塔的拉应力降低而压应力增大,损伤体积比、塑性耗散能、损伤耗散能最大可减小 23.93%以上.塔顶排架结构可以减小进水塔地震动力响应,对进水塔的抗震性能具有积极影响.
Abstract
The top hoist chamber of the intake tower is usually a bent structure,and damage often occurs first during earthquakes,resulting in the inability of the hydropower station to operate normally.In order to explore the influence of bent structure on the dynamic response of intake tower,a study was conducted on the dynamic response of the intake structure of a pumped storage power plant's lower reservoir.Theoretical exploration was conducted based on a simplified system with two degrees of freedom and no damping,and three-dimensional nonlinear finite element numerical simulation method was used to calculate the natural vibration characteristics,displacement,acceleration,stress,damage volume ra-tio,and energy dissipation of the intake tower under two conditions of with and without bent.The response at any time was solved by time history analysis method,the viscoelastic artificial boundary was introduced to simulate the radiation damping effect of foundation.The results show that the intake tower-bent system may produce whiplash effect and reduce the dynamic response of the intake tower during the earthquake.The bent frame at the top of the tower increases the nat-ural frequency of the intake tower by about 2.10%-3.80%,reducing the maximum relative displacement and maximum acceleration of the key points of the tower body by more than 23.94%and 22.30%,respectively.With bent frame,the tensile stress of intake tower decreases but the compressive stress increases,and the damage volume ratio,plastic dissipa-tion energy and damage dissipation energy can be reduced by more than 23.93%.The bent structure at the top of the tower can reduce the seismic dynamic response of the intake tower and has a positive impact on the seismic performance of the intake tower.
关键词
进水塔/排架结构/动力响应/黏弹性人工边界/混凝土塑性损伤Key words
intake tower/bent structure/dynamic response/viscoelastic artificial boundary/concrete damaged plasticity引用本文复制引用
基金项目
中央高校基本科研业务费专项资金项目(B220204001)
云南省重大科技专项计划(202102AF080001)
出版年
2024
NETL
NSTL
万方数据