共查询到19条相似文献,搜索用时 125 毫秒
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为研究多层弹性部件轨道系统的动态特性,提出一种实验室测试方案:首先以锤击法和模态分析为基础,按照实际轨道结构搭建一段25 m长的测试平台,进而在预荷载作用下测试并计算得到轨道系统的固有频率、阻尼比和振动传递率等,最后对比分析道床隔振垫、扣件刚度和预载荷对轨道动态特性影响。结果显示:采用隔振垫能使大于40 Hz的频段具有较好的减振隔振效果,但在小于40 Hz频段会出现较大的振动峰值;随着预载荷增加,20~100 Hz频段的振动传递率急剧增大,并在30 Hz附近形成明显的共振峰值;扣件刚度减小能降低28~100 Hz频段的振动传递率和振动峰值,但同时会增加28 Hz以下频段振动传递率。试验方案和结论为研究减振产品的动态特性和减振效果提供了可靠的试验数据支撑。 相似文献
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利用有限元分析技术对某车型的发动机悬置支架进行了约束模态分析,得到了发动机悬置支架的第一阶模态频率和振型,并对分析结果进行了评价和分析。为了满足NVH性能要求,对悬置支架进行了结构优化,并对优化后的支架进行了验证分析,优化后的悬置支架模态固有频率满足NVH性能要求。 相似文献
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考虑橡胶减振产品刚度易受材料、制造工艺等因素影响,导致刚度上下波动,从而对系统减振隔振性能很大的影响。以某重卡动力总成悬置系统作为研究对象,以悬置刚度为设计变量,固有频率合理配置和解耦率为约束条件,以能量解耦率为目标,对悬置系统进行稳健性优化设计。结果表明,与确定性优化相比,稳健性优化设计不仅能够优化出合理的刚度参数,而且悬置系统NVH性能稳健性和可靠性显著提高,其中主要振动Roll方向频率的sigma水平从2.32sigma提高到3.19sigma,可靠度由94.25%提高到99.85%。 相似文献
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针对电动轻型客车传动轴振动过大的问题,为了提高整车的噪声、振动与声振粗糙度(NVH)水平,对其传动轴中间支撑进行了多目标优化设计,对支承的刚度值进行了仿真分析。首先,介绍了频率比计算设计的过程和优化理论,对某传动轴支承的悬挂质量、固有频率、频率比进行了计算分析;然后,基于多目标遗传算法(NSGA-Ⅱ),以振动传递率、一阶模态变化率、橡胶阻尼比、频率比为约束条件构造了目标函数,运用多目标优化理论对中间支承的刚度进行了重新匹配设计及优化计算,获得了目标刚度值;最后,对优化前后的中间支承刚度值进行了仿真分析,并开展了NVH实车试验验证。研究结果表明:在80 km/h时速下,改进后支架上的振动加速度下降了约19%;优化后的中间支承目标刚度值具有较好的减振效果,减少了传动轴对整车振动带来的负面影响,从而证明了该优化方法的有效性。 相似文献
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为了减小变压器的振动和噪声对居民生活的影响,针对S11-M-630/10型变压器设计了一种新型弹簧减振降噪装置。应用ANSYS软件建立该装置的有限元模型,进行结构动力学分析,得出其固有频率和振动模态,并利用振动传递率和减振效率的数学模型计算出其理论值。有限元仿真分析结果以及振动传递率和减振效率的数学模型对该变压器弹簧减振降噪装置的设计及实现具有重要的指导意义。 相似文献
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悬置系统的设计对车辆NVH性能起着重要作用,影响着整车振动大小及噪声水平。以某车型动力总成悬置系统为载体,基于Virtual.Lab建立的系统分析模型,分别计算了悬置系统固有频率分布、模态解耦率及系统位移量,结果显示:悬置系统固有频率分布不合理,重要方向的解耦率小于80%,且位移量大于10mm,均不满足要求;应用遗传算法,对悬置系统进行优化分析,将系统变量设定为悬置橡胶刚度,固有频率及位移量所要求的范围设定为约束条件,目标为解耦率最大。通过优化悬置橡胶刚度参数,悬置系统的固有频率、位移量可以控制在要求的范围内,并且模态耦合的程度大大降低。 相似文献
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To suppress vertical flexural vibration of a railway vehicle car body, a new passive control method by mounting dampers on the longitudinal beams of the car body underframe is proposed. The method is firstly studied by an Euler-Bernoulli beam model using Green’s functions, then it is further verified by a nonlinear dynamic model of the vehicle. Results show that the car body flexural vibration can be noticeably reduced by this method. It is better to mount the damper near the car body centre. The higher damping coefficient of the damper, the more effective in decreasing the car body first vertical bending vibration. The higher the rigidity of the damper bracket and rubber bush, the better performance of the damper. It is found that when mounting six dampers at proper positions, the damping coefficient of each damper is 1.33×107 N·s/m, even if the first vertical bending frequency of the studied car body is only 7.2 Hz, a very good ride quality will be achieved when the vehicle runs at 250 km/h. 相似文献
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为了有效解决某轻型载货车储气罐支架的断裂故障,首先基于建立的储气罐支架有限元模型进行振动特性分析,分析结果表明其前三阶固有频率接均处于发动机激励频率范围之外,不会产生共振。其次测试各种道路的时域载荷,测试结果表明其中角度搓板路的激励频率与储气罐支架第一阶固有频率相接近,从而引起共振,不满足振动特性要求。然后对其进行振动强度分析,分析结果表明其应力水平不达标,其最大应力点与开裂处一致。再对其进行振动疲劳寿命预测分析,分析结果表明其疲劳寿命也不达标,其危险点也与失效位置相同。再采用集成平台对储气罐支架的结构进行优化设计,优化之后其模态频率、振动强度和振动疲劳均符合性能要求,并且其重量也有所减轻,总体优化效果较佳。最后整车试验结果表明优化之后储气罐支架的振动大幅度降低,并且没有发生失效。 相似文献
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Topology optimization is very useful engineering technique especially at the concept design stage. It is common habit to design
depending on the designer’s experience at the early stage of product development. Structural analysis methodology of compressor
bracket was verified on the static and dynamic loading condition with 2 bracket samples for the topology optimization base
model. Topology optimization is able to produce reliable and satisfactory results with the verified structural model. Base
bracket model for the topology optimization was modeled considering the interference with the adjacent vehicle parts. Objective
function was to minimize combined compliance and the constraint was the first natural frequency over 250 Hz. Multiple load
cases such as normal mode calculation and gravity load conditions with 3-axis direction were also applied for the optimization,
expecting an even stress distribution and vibration durability performance. Commercial structural optimization code such as
optistruct of Altair Engineering was used for the structural topology optimization. Optimization was converged after 14 iterations
with the satisfaction of natural frequency constraint. New bracket shape was produced with the CATIA based on the topology
optimization result. The new bracket from topology optimization result was compared with the traditional concept model and
topology optimization base model under 4 load cases. 14 % 1’st natural frequency of new bracket with only 4 % mass increment
increased compared to the concept model. 31 % mass decreased compared to the base model without the increment of stress under
gravity load cases. It was analyzed thata new bracket would not fail during a vibration durability test, and these results
were verified with a fabricated real sample under the durability condition. 相似文献
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石英音叉陀螺的固支结构对陀螺器件的性能影响很大.提出一种新型固支结构的石英音叉陀螺,把固支结构的支撑梁设计在元件拾取运动零位移线处,目的在于提高陀螺对外界振动和温度变化的抗干扰能力,从而改善零位稳定性.运用ANSYS软件对新结构做仿真验证,结果表明新结构在元件灵敏度、抗振动等重要性能上都有一定提高.新结构同时能缩短元件制造流程,更易工程实现. 相似文献
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