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
大型同步调相机配套管道异常振动问题,不仅会降低管道的使用寿命,还会影响调相机润滑油和冷却液的供应,严重时甚至会造成重大安全事故,危害电力系统的稳定性。以某特高压换流站的同步调相机润滑油供油管道为研究对象,使用现场测量、流...大型同步调相机配套管道异常振动问题,不仅会降低管道的使用寿命,还会影响调相机润滑油和冷却液的供应,严重时甚至会造成重大安全事故,危害电力系统的稳定性。以某特高压换流站的同步调相机润滑油供油管道为研究对象,使用现场测量、流固耦合和谐响应分析等多种方法,研究了管道振动的产生原因和机制。结果表明,由调相机本身产生的周期性激振力是管道振动的主要原因。进一步提出基于调谐质量阻尼器(Tuned Mass Damper,TMD)的管道减振措施,试验和仿真数据表明,在润滑油供油管道系统4和5、6和7支吊架中间位置各安装一个TMD,减振效果最佳,可将该管系的振动加速度降低90%以上,具有良好的减振效果。展开更多
基金Projects(51708558,51878673,U1734208,52078485,U1934217,U1934209)supported by the National Natural Science Foundation of ChinaProject(2020JJ5740)supported by the Natural Science Foundation of Hunan Province,China+1 种基金Project(KF2020-03)supported by the Key Open Fund of State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures,ChinaProject(2020-Special-02)supported by the Science and Technology Research and Development Program of China Railway Group Limited。
文摘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.
文摘大型同步调相机配套管道异常振动问题,不仅会降低管道的使用寿命,还会影响调相机润滑油和冷却液的供应,严重时甚至会造成重大安全事故,危害电力系统的稳定性。以某特高压换流站的同步调相机润滑油供油管道为研究对象,使用现场测量、流固耦合和谐响应分析等多种方法,研究了管道振动的产生原因和机制。结果表明,由调相机本身产生的周期性激振力是管道振动的主要原因。进一步提出基于调谐质量阻尼器(Tuned Mass Damper,TMD)的管道减振措施,试验和仿真数据表明,在润滑油供油管道系统4和5、6和7支吊架中间位置各安装一个TMD,减振效果最佳,可将该管系的振动加速度降低90%以上,具有良好的减振效果。
