共查询到19条相似文献,搜索用时 140 毫秒
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对低温环境下(-30℃)的250km/h高速列车车内客室端部噪声进行测试,深入分析了运行环境温度对车内噪声的影响。通过对比夏季、冬季两种季节因素,掌握了不同环境下高速列车的车内振动噪声特性、车下声源特性和声振传递路径,研究了低温环境下的高速列车减振降噪技术,以提高低温环境下高速列车的车内噪声性能。研究结果表明,车内客室端部噪声异常问题是由于受到列车250km/h匀速运行时的过枕垮频率激励,而冬季运行时转向架区域减振性能下降,使得该频率更容易传递至车内所致,并激发车内客室空腔的声学模态。通过从传递路径上进行控制,使用一种金属减振器代替原有地板的支撑结构,优化车体内地板和外地板之间的弹性支撑,能够有效改善低温环境下高速列车车内客室端部异常噪声问题。 相似文献
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地铁列车低噪声设计最基本和关键的第一步是为轨道车辆各主要部件分配声学指标,使其噪声性能满足低噪声设计目标限值,为此,本文提出一种基于SEA-PSA的地铁噪声顶层指标分解方法.首先,以一节地铁列车作为算例,基于统计能量分析(SEA)理论建立车内噪声模型并验证.然后,基于参数灵敏度分析理论,使用向前差分计算不同输入参数的灵敏度,包括通过空气路径传播的声源激励、通过结构路径传播的振源激励以及车体板件隔声,通过灵敏度分析法获得关键参数.得到关键输入参数后为其分配声学指标,制订声规范.结果表明:轮轨噪声和空调通风管道噪声及地板、侧墙、车窗的隔声是地铁列车运行时影响车内噪声的关键参数,为其分配声学指标可降低客室内声压级3 dB,满足限值要求.本文提出的基于SEA-PSA顶层指标分解方法是科学的、合理的,是实现车内低噪声设计的有效方法. 相似文献
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针对油液减振器异响检测、活塞杆加速度测试方法以及对弹性与刚性两种夹持方式下外特性测试结果存在差异等问题,开展了对比在不同安装方式下油液减振器外特性测试的试验研究,设计了分别采用常规外特性测试专用夹具(刚性夹持)和活塞杆加速度夹具(弹性夹持)的减振器外特性测试对比试验,对常规外特性测试专用夹具和活塞杆加速度夹具的结构和功能特点作了分析,进而对两套夹具造成外特性曲线存在差异的原因进行了研究,根据油液减振器工作原理及结构参数,建立了阻尼力模型并根据现有理论和试验结果进行了模型修正仿真。研究结果表明,两种夹持方式的测试结果对判定减振器外性能可以通用,而且还能够从不同方面反映出减振器内部的动态性能。 相似文献
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设计了磁流变减振器磁芯磁路,建立了磁路的仿真模型,仿真研究了磁路的磁场特性,用实验的方法对仿真模型进行了验证和修正;在此基础上,建立了整个磁流变减振器的仿真模型,仿真研究了其磁场分布规律及不同参数下阻尼孔附近的磁通密度.研究结果表明,磁芯直径、工作缸壁厚、阻尼通道长度和线圈电流是影响磁场特性的主要因素,合理选择磁路结构参数可使其性能得到最大发挥.设计并制造出一种车辆单筒充气式磁流变减振器,对其进行了台架试验,得到不同电流下的减振器示功特性图,研究发现,通过调节减振器励磁线圈中的电流获得不同强度的磁场,在磁场作用下,磁流变液粘度发生变化,从而改变减振器的阻尼特性,减振器的饱和工作电流约为2A.试验验证了磁路设计的正确性,并为实现车辆磁流变半主动空气悬架控制研究奠定了基础. 相似文献
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针对高速列车受电弓区噪声相对较高的问题,提出受电弓减振安装方案,并在模拟实车环境下验证了其降噪效果和可靠性。首先,在某高速列车上进行了线路运行条件下受电弓区振动和噪声测试,分析发现结构振动是该区域噪声传播的重要方式,设计了一种独特的锥形椭圆结构减振座,用于受电弓弹性安装;其次,搭建了模拟现车试验台,验证减振座的降噪效果;最后,进行了总计252万次的疲劳试验以验证减振座的可靠性。试验结果表明,该减振座能够有效减小受电弓振动对车体的激励,从而降低该区域的噪声,降噪效果约为4dB(A),其疲劳可靠性能够满足线路运行要求。 相似文献
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高速铁路声屏障几何形状声学性能数值模拟 总被引:1,自引:0,他引:1
为了弄清声屏障几何形状对高速铁路户外噪声的降噪机理和降噪效果,采用二维边界元法建立高架桥铁路声屏障噪声预测模型,分析不同几何形状结构参数对降噪性能的影响。分析中考虑列车运行速度、声源分布及频谱特性对插入损失的影响,根据车外声源识别结果建立符合我国高速铁路的声源模型;考虑车体-轨道-声屏障之间的多重反射,建立边界元计算模型;对顶部倾斜、T型、多重绕射边型、Y型、圆柱型等声屏障的结构参数的影响进行调查分析,分析中分别考虑插入损失、场点频谱及声场变化规律。研究结果表明,Y型声屏障降噪效果最好,平均插入损失提高3.4 dB(A)其次为圆柱型声屏障。 相似文献
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Noise is one of the key issues in the operation of high-speed railways, with sound source localisation and its transfer path as the two major aspects. This study investigates both the exterior and interior sound source distribution of a high-speed train and presents a method for performing the contribution analysis of airborne sound with regard to the interior noise. First, both exterior and interior sound source locations of the high-speed train are identified through in-situ measurements. Second, the sound source contribution for di erent regions of the train and the relationships between the exterior and interior noises are analysed. Third, a method for conducting the contribution analysis of airborne sound with regard to the interior noise of the high-speed train is described. Lastly, a case study on the sidewall area is carried out, and the contribution of airborne sound to the interior noise of this area is obtained. The results show that, when the high-speed train runs at 310 km/h, dominant exterior sound sources are located in the bogie and pantograph regions, while main interior sound sources are located at the sidewall and roof. The interior noise, the bogie area noise and the sound source at the middle of the coach exhibit very similar rates of increase with increasing train speed. For the selected sidewall area, structure-borne sound dominates in most of the 1/3 octave bands. 相似文献
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While introducing foreign advanced technology and cooperating with Chinese famous research institutes,the high-speed vehicles are designed and take the major task of passenger transport in China.In high-speed vehicle,the characteristic of shock absorber is an important parameter which determines overall behavior of the vehicle.The most existing researches neglect the influence of the series stiffness of the shock absorber on the vehicle dynamic behavior and have one-sided views on the equivalent conicity of wheel tread.In this paper,a high speed passenger vehicle in China is modeled to investigate the effect of the parameters taking series hydraulic shock absorber stiffness into consideration on Ruzicka model.Using the vehicle dynamic model,the effect of main suspension parameters on critical speed is studied.In order to verify the reasonableness of shock absorber parameter settings,vibration isolation characteristics are calculated and the relationship between suspension parameters and the vehicle critical hunting speed is studied.To study the influence of equivalent conicity on vehicle dynamic behavior,a series of wheel treads with different conicities are set and the vehicle critical hunting speeds with different wheel treads are calculated.The discipline between the equivalent conicity of wheel tread and critical speed are obtained in vehicle nonlinear system.The research results show that the critical speed of vehicle much depends on wheelset positioning stiffness and anti-hunting motion damper,and the series stiffness produces notable effect on the vehicle dynamic behavior.The critical speed has a peak value with the equivalent conicity increasing,which is different from the traditional opinion in which the critical speed will decrease with the conicity increasing.The relationship between critical speed and conicity of wheel tread is effected by the suspension parameters of the vehicle.The study results obtained offer a method and useful data to designing the parameters of the high speed vehicle and simulation study. 相似文献
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针对传统A计权声压级评价指标对噪声低频成分衰减较大,常常出现车内声压级达标,声品质不合格的问题。引入心理声学参数的响度参量,利用虚拟仿真技术分析评价车内声学特性。建立驾驶室声-固耦合有限元模型,结合试验激励数据,进行基于模态的声学响应计算。在Matlab平台上,建立车内声品质客观心理声学参数响度的计算模型,对比预测驾驶室内场点的声压级和响度分布,结合声压级和响度结构板块贡献量分析,研究声压级和响度参量评价驾驶室结构特性的差别并识别驾驶室主要噪声源。以此为基础指导优化驾驶室结构阻尼铺设位置,综合提高车内声学品质。 相似文献
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首先,采用脉冲响应衰减法测试了敷设阻尼薄板的阻尼损耗因子,分析了阻尼敷设比例及薄板的悬挂状态对薄板阻尼损耗因子的影响;其次,在混响-全消室中测试了敷设阻尼薄板的隔声量,比较了不同阻尼敷设比例薄板的测试结果;最后,建立了敷设阻尼薄板隔声量计算分析模型,隔声量计算值与试验值吻合较好,验证了计算模型的有效性。研究了敷设阻尼材料厚度与敷设比例对薄板结构隔声性能的影响,综合考虑轻量化和隔声性能,分析了阻尼材料厚度与敷设比例对薄板降噪效率的影响,并以降噪效率最大为目标进行了薄板隔声特性的优化。 相似文献
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以某全地域机动车驾驶室为研究对象,建立驾驶室的有限元模型,验证了有限元模型的有效性。以此有限元模型为基础构建驾驶室谐响应模型,进行谐响应分析,发现驾驶室后壁板的振动是引起驾驶室内部噪声的主要原因。研究驾驶室内部噪声特性,分别进行了声学空腔模态分析和声固耦合模态分析,发现声固耦合系统声压分布比较均匀,大部分呈现局部模态,主要原因可能是驾驶室后壁板的振动。通过驾驶员耳旁声压分析发现增加驾驶室后壁板的厚度,可以在一定程度内降低驾驶室内部噪声对驾驶员的影响,为同类驾驶室通过依靠结构改进来改善声场环境提供了案例依据。 相似文献
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Investigation on Major Noise Sources of Vehicle Diesel Engine Based on Sound Intensity Measurement 总被引:1,自引:0,他引:1
In order to reduce the noise and vibration of the diesel engine,it is crucial to exactly identify the engine noise source character.Based on "two-microphone" method,the sound intensity measurement of a vehicle four-stroke diesel engine was carried out in a hemi-anechoic chamber.Then the sound intensity contour maps were obtained from the measurement results and the main noise components of different frequencies on all the measurement surfaces were picked out to construct contour maps.By analysizing the relationship between the characteristics of contour maps and the space distribution of the engine compartment,the major sources of the exterior radiation noise of the diesel engine were identified.The results provided a creditable basis for improving the noise performance of the engine in the next phase. 相似文献