城市轨道交通振动与噪声

随着经济的发展 ,城市轨道交通的振动和噪声问题越来越引起人们的重视。叙述了轨道结构振动的产生原因及环境振动的评价指标 ,分析了铁路噪声的组成及对环境噪声的评价标准。通过对国内外资料的分析 ,认为轮轨噪声是城市轨道交通噪声的主要组成部分 ,要对轨道交通减振降噪 ,降低轨道结构的振动是关键。最后提出对轨道交通减振降噪的一些建议。     

水面舰艇装舰设备弹性安装方式的选择

从舰船总体设计师的角度,论述了水面舰艇装舰设备特别是辅机声源弹性安装方式的选定准则。讨论了单级隔振及一般浮筏方式在水面舰艇上的适应性及应用前景,以舰船总体要素及声平衡设计的理念为基础,指出了旋转机电设备被动隔振方式存在的相关技术问题及单级隔振所能发挥的声学潜能。     

单铁磁悬浮控制系统的动力学特性研究

建立单铁悬浮控制系统的非线性闭环状态空间模型,研究该系统的动力学特性,推导了三个主要控制参数与系统动力学特性的基本约束关系,特别是对单铁磁悬浮系统的自激振动给出了严格的理论解释。文章所得到的结论与实验结果一致。     

邻近病害铁路隧道山体爆破振动控制

以在病害铁路隧道附近进行了多次山体爆破为例，系统地介绍了爆破振动控制的要求、方法、过程、效果及值得探讨的事项，与传统的爆破振动控制理念相比有不同之处。可为同类条件下进行爆破施工提供借鉴。     

隔振腔四层减振系统的仿真设计

隔振腔作为伽玛定位仪器的三个减振环节之一,其动力学模型及其特征参数都比较复杂。本文在隔振腔动力学简化模型的基础上,建立隔振腔的四层动力学微分方程组,输入各层的等效虎克系数和等效阻尼,通过采用MATLAB软件对动力学微分方程组的数值仿真计算,来准确表达系统的输出响应特性。清华大学力学实验室对隔振腔进行了多组冲击载荷实验测试,证明模型的建立和特征参数设计的正确性。     

一种简捷直观的多自由度振系的建模方法

利用拉格朗日方法推导多自由度振动系统的动力学模型的关键是能够准确快捷地推导出弹簧两端的相对位移和阻尼器两端的相对速度，为此提出了一种简捷直观的平板图法，并以推导某类轿车动力总成一副车架二级悬置隔振系统的12自由度动力学模型为实例，阐述了平板图法在多自由度振系建模中的应用，总结了应用平板法快速求解弹簧阻尼器相对位移和相对速度的规律，实例推导结论表明平板图法的应用可以使多自由度振系的建模更加准确快捷。     

混合动力客车超级电容系统振动失效研究

对某款混合动力客车失效超级电容模组与模组安装位置之间的关系进行研究,针对模组失效原因提出改进建议。     

斜拉索涡激振动的被动自吸吹气流动控制

圆形斜拉索长细比大、阻尼及刚度小，因而其经常发生风致振动，尤其是涡激振动。涡激振动是一种限幅振动，其发生风速较低，因而斜拉索经常发生涡激振动现象，为此提出一种被动自吸吹气流动控制措施来抑制斜拉索涡激振动。通过节段模型气弹试验得到，被动吸吹气控制方法在套环间距适当下使得斜拉索涡激振动区间变窄，甚至可以完全抑制其发生涡激振动。通过分析斜拉索节段模型表面压力分布，得到被动自吸吹气能大幅度降低压力脉动值和脉动风荷载；且模型背风面的平均压力值的平台区也有所提升，表明平均阻力也有所减小。频谱分析表明：此控制方法改变了旋涡脱落模式及脱落强度。最后由尾流速度剖面可得，被动吸吹气流动控制方法缩小了模型尾流区宽度，尾流中的速度脉动也极大降低。折算风速为5.99时，对尾流速度时程做频谱分析可得，吸吹气控制方法能抑制住无控圆柱模型尾流中周期性交替脱落的旋涡。套环控制方法应用于三维柔性索性索模型上，能极大地降低柔性斜拉索的前三阶涡激振动幅值，同时发现套环间距越小，控制效果越强。     

On the interest of integrating vehicle dynamics for the ground propagation of vibrations: the case of urban railway traffic

This paper presents a complete numerical model for studying the vertical dynamics of the vehicle/track interaction and its impact on the surrounding soil, with the emphasis on vehicle modelling. A decoupling between the track and the soil is proposed, due to the difficulty of considering all the subsystem components. The train/track model is based on a multibody model (for the vehicle) and a finite element model (for the track). The soil is modelled using an infinite/finite element approach. Simulations of both models are carried out in the time domain, which is better able to simulate the propagation of the vibration waves and to take into account the possible nonlinearity of a component. The methodology is applied in the case of an urban tram track and validated with the available experimental data. Models for the tram, the track and the soil are described. Results from the complete model of the vehicle and a simple model, based on an axle load, are compared with experimental results and the benefits of a complete model in the simulation of the ground vibration propagation induced by railway vehicles are demonstrated. Moreover, a parametric study of the vehicle wheel type is conducted, which shows the advantage of a resilient wheel, for various rail defects.     

Influence of tyre–road contact model on vehicle vibration response

The influence of the tyre–road contact model on the simulated vertical vibration response was analysed. Three contact models were compared: tyre–road point contact model, moving averaged profile and tyre-enveloping model. In total, 1600 real asphalt concrete and Portland cement concrete longitudinal road profiles were processed. The linear planar model of automobile with 12 degrees of freedom (DOF) was used. Five vibration responses as the measures of ride comfort, ride safety and dynamic load of cargo were investigated. The results were calculated as a function of vibration response, vehicle velocity, road quality and road surface type. The marked differences in the dynamic tyre forces and the negligible differences in the ride comfort quantities were observed among the tyre–road contact models. The seat acceleration response for three contact models and 331 DOF multibody model of the truck semi-trailer was compared with the measured response for a known profile of test section.