共查询到18条相似文献,搜索用时 109 毫秒
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以某发动机悬置为研究对象,建立了一个悬置系统的三维动力学模型。以动力总成的参数为设计变量,以固有频率的合理配置和悬置系统能量解耦达标为设计目的,对悬置系统进行了详细分析,建立其六自由度自由振动运动方程,并找出了悬置三向刚度的合理匹配。同时,也为Matlab在振动方程求解中的应用提供了一个范例,为发动机悬置的设计建立了一个有效可行的计算方法。 相似文献
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发动机悬置系统的动静态特性是影响坦克车辆的机动性和人员舒适性的重要因素之一。由于发动机振动频率随着工况的改变而发生改变,利用磁流变弹性体的刚度可控特性,采用避开车身振动频率的方式,提高悬置系统隔振效果。基于建立的发动机两自由度动力学模型,获得避开机身共振频率所需磁流变弹性体悬置系统的刚度变化范围。设计了一种新型的压缩式磁流变弹性体隔振器,用有限元法对隔振器的磁路进行设计和分析,并采用万能材料试验机对该隔振器进行了测试。试验结果表明,通过改变外加电流大小,该隔振器满足了坦克发动机悬置的刚度变化范围。 相似文献
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汽车发动机悬置系统解耦方法研究 总被引:24,自引:0,他引:24
本文提出了一种通过对汽车发动机悬置系统刚度矩阵解耦而实现系统解耦的新方法,应用该法对悬置参数进行优化计算,可以实现发动机悬置系统沿z向和θx向的振型解耦,以达到控制整车振动的目的。 相似文献
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针对客车发动机悬置设计,提出了"两维刚度元素优化法",以Matlab软件为平台,开发了一套实现客车悬置优化设计的计算机程序。该程序能快速地完成发动机悬置的优化设计,并能有效地提高悬置设计的隔振性能。并用ADAMS软件对其进行建模论证,证明该方法可行、实用。 相似文献
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在动力总成悬置的制造、安装和汽车的使用过程中,悬置的刚度存在一定程度的不确定性。因此,悬置系统的频率和解耦率必然不是确定值。为研究悬置系统频率和解耦率的变化特征,进而解其性能的稳健性,文中给出一种区间分析方法。在已知悬置刚度的变化范围而不需解其统计特性的情况下,用区间数学中的区间数描述其变化的不确定性,基于组合方法计算悬置系统固有频率和解耦率的精确变化范围。给出区间可靠度的计算公式,用于表征悬置系统频率和解耦率的设计稳健性。计算某轿车悬置系统的频率以及沿垂直方向和绕发动机曲轴扭转方向解耦率的区间可靠度。计算结果表明,当悬置刚度在其设计名义值附近波动时,动力总成悬置系统的悬置刚度需要进行优化,以提高固有频率及垂直方向和绕发动机曲轴扭转方向解耦率的设计稳健性。 相似文献
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对燃料电池车进行了振动噪声测试,采用分别运行法采集了在空气辅助系统和氢气辅助系统分别独立运行工况下的振动噪声信号。并通过对测试数据进行频谱分析等,确定了燃料电池车振动噪声的主要频率特性及主要振动噪声源为空气辅助系统和氢气辅助系统以及燃料电池冷却水泵等,同时针对主要振动噪声源提出了一些行之有效的改进方案,尤其是对风机及氢气辅助系统箱体的改进提出了见解性的改进意见。通过现代信号分析技术进行振动噪声源识别,确定主要的振动和噪声源,并对燃料电池车的减振降噪提出了可行性方案,是实施正确减振降噪措施的前提。 相似文献
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B. WITHY A. JAMES J. WILLIAMS 《Fatigue & Fracture of Engineering Materials & Structures》2012,35(1):37-44
Between 2005 and 2007 serious flight safety concerns arose when a small fleet of single engine basic trainer aircraft experienced five critical failures of engine driven fuel pump (EDFP) couplings, and a further instance of a cracked coupling. Consequent investigations showed that the coupling fractures were likely to have been caused by a combination of reverse torsional loading and bending. Engine ground runs were then carried out to evaluate linear and torsional engine vibration levels in the drive train affecting the fuel pumps. Analysis of the vibration data indicated that engines, which had caused pump‐coupling failures exhibited high‐amplitude torsional vibration at certain power settings. The excessive vibration level was eventually attributed to detuning of the crankshaft counterweight dampers. This investigation resulted in a change to the maintenance practises on the aircraft in question and no fuel pump failures have occurred since December 2008. 相似文献
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This paper introduced the design of the hybrid powertrain of the Fuel Cell City Bus demonstrated in 2008 Beijing Olympic Games. The configuration of the hybrid fuel cell powertrain was introduced. The safety of hydrogen storage and delivery system, the hydrogen leakage alarm system were developed. The real-time distributed control and diagnosis system based on the Time Trigger Controller Area Network (TTCAN) with 10 ms basic control period was developed. The concept and implementation of processor (or controller) monitor and process (or task) monitor technique based on the TTCAN were applied in this paper. The fault tolerant control algorithm of the fuel cell engine and the battery management system were considered. The demonstration experience verified that the fault tolerant control was very important for the fuel cell city bus. 相似文献
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Effects of viscoelastic properties of engine cover sealing system on noise and vibration attenuation
Automobile engine cam cover seals are made of elastomeric materials and used to seal the interfaces between cover and underlying
structures. The design of engine cam cover seals has been traditionally focused on the sealability aspects. Recently, there
has been additional demand that these seals be designed as vibration isolators to attenuate the radiated noise from the engine.
To accomplish this goal, the frequency-dependent viscoelastic properties of the sealing components will have to be considered
during the design process. This article examines the frequency-dependent viscoelastic properties of some commonly used elastomeric
seals at various mounting configurations. An analytical spatial transmissibility method is used for evaluating the design
of elastomeric sealing system for reducing vibration and radiated noise. 相似文献