期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
后临界湍流区间内旋转薄壳结构振动演化与作用机制实测研究 被引量:1
1
作者 王浩 柯世堂 《力学学报》 EI CSCD 北大核心 2019年第1期111-123,共13页
载荷的时变特征可能会对结构振动强度和能量作用机理产生重要影响,火/核电厂最重要的大型建筑结构均为典型的旋转薄壳结构(如冷却塔、烟囱等).为揭示后临界湍流区间内旋转薄壳结构的振动演化特征及其作用机制,实测了后临界雷诺数(Re3.5&... 载荷的时变特征可能会对结构振动强度和能量作用机理产生重要影响,火/核电厂最重要的大型建筑结构均为典型的旋转薄壳结构(如冷却塔、烟囱等).为揭示后临界湍流区间内旋转薄壳结构的振动演化特征及其作用机制,实测了后临界雷诺数(Re3.5×10~6)条件下8座典型旋转薄壳结构的振动响应.首先,在对实测响应进行降噪滤波处理后进行了不同时距的信号非平稳识别,基于非平稳分析模型对响应的时变均值和极值估计进行研究,并基于多尺度小波变换的演化谱方法开展了响应的频域演变特性研究.在此基础上,探讨了结构风振响应的共振分量占比及其效应,识别了结构的自振频率和阻尼比,并以结构基频为划分依据分别讨论了不同旋转薄壳结构的阻尼作用机制.研究结果表明:(1)旋转薄壳结构在后临界湍流区间内风致振动响应表现为强度非平稳、频率平稳的演化特性;(2)后临界湍流区间内的旋转薄壳结构的风振问题应区分准静力作用点与共振激发点分别进行研究,不同共振激发点的功率谱分布形式较为相近,而准静力作用点的功率谱分布规律差异较大;(3)共振激发点的振动能量分布呈现明显的分段趋势,基于本文大量实测分析结果回归得出适用于共振激发点的三阶段共振谱表达式;(4)借助本文提出的等效阻尼比概念拟合出此类结构的阻尼比预测公式,论证了目前工程中通用的5%阻尼比取值的不合理性. 展开更多
关键词 旋转薄壳结构 后临界湍流区间 现场实测 振动演化 作用机制
在线阅读 下载PDF
Effects of wheelset vibration on initiation and evolution of rail short-pitch corrugation 被引量:6
2
作者 闫子权 谷爱军 +2 位作者 刘维宁 V.L.Markine 梁青槐 《Journal of Central South University》 SCIE EI CAS 2012年第9期2681-2688,共8页
The initiation and evolution of short-pitch corrugation in Beijing metro line 4 was studied from the viewpoint of wheelset vibration.A three-dimensional elastic model was set up.Numerical simulations were undertaken w... The initiation and evolution of short-pitch corrugation in Beijing metro line 4 was studied from the viewpoint of wheelset vibration.A three-dimensional elastic model was set up.Numerical simulations were undertaken with this model to analyze the corrugation by the wheelset vertical vibration and torsional vibration.Based on numerical results,the relation between rail corrugation and wheelset vibration,and the relation between the position of electromotor and wheelset vibration were indicated.It is found that avoiding the wheelset-rail resonance is one method of controlling the rail short-pitch corrugation and solving the vibration and noise problem in metro lines. 展开更多
关键词 rail corrugation wheelset vertical vibration wheelset torsional vibration finite element modeling
在线阅读 下载PDF
Probabilistic model and analysis of coupled train-ballasted track-subgrade system with uncertain structural parameters 被引量:7
3
作者 MAO Jian-feng XIAO Yuan-jie +2 位作者 YU Zhi-wu Erol TUTUMLUER ZHU Zhi-hui 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第7期2238-2256,共19页
Random dynamic responses caused by the uncertainty of structural parameters of the coupled train-ballasted track-subgrade system under train loading can pose safety concerns to the train operation.This paper introduce... Random dynamic responses caused by the uncertainty of structural parameters of the coupled train-ballasted track-subgrade system under train loading can pose safety concerns to the train operation.This paper introduced a computational model for analyzing probabilistic dynamic responses of three-dimensional(3D)coupled train-ballasted track-subgrade system(TBTSS),where the coupling effects of uncertain rail irregularities,stiffness and damping properties of ballast and subgrade layers were simultaneously considered.The number theoretical method(NTM)was employed to design discrete points for the multi-dimensional stochastic parameters.The time-histories of stochastic dynamic vibrations of the TBSS with systematically uncertain structural parameters were calculated accurately and efficiently by employing the probability density evolution method(PDEM).The model-predicted results were consistent with those by the Monte Carlo simulation method.A sensitivity study was performed to assess the relative importance of those uncertain structural parameters,based on which a case study was presented to explore the stochastic probability evolution mechanism of such train-ballasted track-subgrade system. 展开更多
关键词 coupled train-ballast-subgrade system structural parameter uncertainty stochastic dynamic analysis probability density evolution method wheel-rail interaction
在线阅读 下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部