共查询到19条相似文献,搜索用时 296 毫秒
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针对某车辆在行驶试验时,在车速57 km/h时出现低频5.4 Hz的驾驶室异常振动的现象,振动形式为俯仰振动,人体乘坐舒适性主观感觉很差。先后采用多种常规振动分析试验方法对该车进行振动分析,也未能分析出引起驾驶室异常振动的原因。最后对该车的车架和驾驶室进行模态试验分析,分析判断得出该车在行驶时驾驶室异常振动的频率与车架整体一阶弯曲时的接近,由此判断该车驾驶室异常振动是由车架整体-阶弯曲引起的。根据试验分析结果,文章最后对某车问题的改进方案综合评价后提出了合理的改进方案。 相似文献
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郑郧 《中国汽车保修设备》1995,(3):13-16
本文作者提出了评价汽车平衡顺性的综合指标一汽车振动舒适度CV;并通过对ISO2631,GB4970,GB/12477等标准的研究,用振动舒适度将汽车座椅处的振动加速度均方振值与人对汽车振动舒适性的主观感觉联系起来,并运用不同车速,测量位置的加权矩阵函数计算出汽车总的振动舒适性指标,用于评价和比较汽车的振动舒适性,解决了由于不同车速,测点振动不同带来汽车平顺性难以评价和比较的问题,并实际应用于某旅行客车振动平顺性的测量和评价中,取得子满意的效果。 相似文献
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两自由度人体振动模型及其在汽车平顺性试验中的应用 总被引:1,自引:0,他引:1
本文论述了汽车平顺性随机输入试验时使用人体振动模型作为座椅载荷的必要性。通过人体动态响应试验建立了两自由度人体模型的数学模型,进而介绍了人体动态参数的识别方法和人体模型的设计原则。试验证实,这种人体振动模型完全可以摸拟坐着的人对铅垂振动的动态响应,可以作为汽车平顺性试验和座椅动态响应试验的测试设备。 相似文献
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汽车中人体振动的评价方法研究 总被引:3,自引:1,他引:2
对国际标准ISO2631新草案进行了研究,应用新草案对各类汽车的人体振动进行了测试分析,确定了影响人体振动舒适性的主要振动轴向。比较了舒适性评价法与总加权值法的评价结果的差异。通过主观评价验证了舒适性评价法能真实地反映人对振动的感觉,并建立了总乘坐值指标的限值。 相似文献
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为采用人-椅接触面的体压分布来表征汽车座椅的振动舒适性,在6种不同幅值的低频垂向激励下,以12名受试者为对象,进行汽车座椅振动舒适性主客观试验,以获得体压分布指标。对振动加速度和体压分布的测试结果进行分析,以提取加权加速度均方根值、平均压力均值、最大压力均值和平均压力变化率与法向力变化率的均方根值等客观评价指标。运用非参数统计方法对主客观指标进行相关分析,结果表明,平均压力均值、最大压力均值与主观不舒适性评分的相关性较弱(β=0.26,0.10),而平均压力变化率和法向力变化率的均方根值与主观不舒适性评分具有较强的相关性(β=0.83,0.85)。最后利用史蒂文斯幂定律对主客观参量进行关联性分析,结果表明,与加权加速度均方根值指标相比,平均压力变化率和法向力变化率的均方根值与主观不舒适性评分均具有较高的关联性(R2>99.0%),可作为体压分布评价指标来表征汽车座椅的振动舒适性。 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(10):1548-1567
Vibration accelerations were measured on a compact wheel loader during 11 operations with two drivers and with/without the activated boom suspension system (BSS). Two standards, ISO 2631-1 (1985) and ISO 2631-1 (1997), were used to assess the effect of wheel loader vibration on comfort. The assessment results of ISO 2631-1 (1985) showed that vibration in the frequency range from 4 to 20 Hz in the vertical direction and in the frequency range from 1.6 to 3.15 Hz in the vertical and driving directions plays an important role in comfort assessment. The overall total values of vibration measured on the wheel loader in all operations exceeded the ‘uncomfortable’ boundary specified in ISO 2631-1 (1997). The speed had a larger influence on the vibration intensity than the bucket load, the BSS or the driver biodynamic response during driving. During driving and V-cycle, the difference of vibration intensity with two drivers in the z-direction is larger than that in the x- and y-direction. 相似文献
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针对某城市大型高架桥爆破拆除工程,采用动力有限元法计算了桥梁塌落触地引起的振动响应,并从幅值、频谱成分及衰减特性等方面探讨了振动的传播规律。计算结果表明:塌落触地振动随着距离的增加而衰减显著;竖向振动响应明显大于径向振动;塌落触地振动的振动能量主要分布在0~50Hz频率范围内,且随着距离的增加,低频成分逐渐占主导地位。 相似文献
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汽车脉冲输入平顺性评价指标限值的研究 总被引:13,自引:2,他引:13
在分析了脉冲输入下人体所受到的振动速度响应到基础上,运用ISO2631新草案对人体健康的评价指标和限值,提出了脉冲输入下汽车平顺性评价指标的限值,最后以东风EQ2102C型军用越野汽车为例,说明了脉冲输入下汽车行驶平顺性的评价过程。 相似文献
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S. J. Ahn 《International Journal of Automotive Technology》2010,11(6):909-916
Shock-type vibrations are frequently experienced in vehicles excited by impulsive input, such as bumps in the road, and cause
discomfort. Current national and international standard weightings were primarily developed for assessing exposure to sinusoidal
or random vibrations and not impulsive excitations or shocks. In this experimental study, various shock signals were systematically
produced using the response of a one degree-of-freedom vibration model to hanning-windowed half-sine force input. The fundamental
frequency of the shock was varied from 0.5 to 16 Hz at a step of 1/3 of an octave. The magnitude estimation method was used
for fifteen subjects to compare the discomfort of shocks with various unweighted vibration dose values between 0.35 ms−1.75 and 2.89 ms−1.75 at each frequency. The equivalent comfort magnitude of shock showed greater sensitivity at frequencies less than 0.63 Hz
and at the resonance frequency of the human body between 5.0 Hz and 6.3 Hz. The frequency weighting constructed by using both
the equivalent comfort magnitude and the growth rate of discomfort obtained in this study was compared with the current standard
weightings, Wb of BS 6841 and Wk of ISO 2631. The derived weightings for shock were applied to the acceleration of the shocks, and an enhanced correlation
was proved between the magnitude estimations and the weighted physical magnitude of shock. 相似文献
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以青岛地铁施工过程中浅埋段隧道下穿建筑物为例,运用HHT分析理论结合MATLAB软件研究了爆破振动监测信号的时频关系,分析雷管的起爆时间间隔,为振动控制提供理论依据。通过分析发现:1)爆破振动信号的频率基本在90 Hz以下,优势频率范围为20~70 Hz;2)根据《爆破安全规程》规定的安全允许标准,3号民房爆破安全允许振速可定为2.0 cm/s,设计振速1.0cm/s较为保守;3)不考虑雷管自身延时误差的情况下,60 ms将是雷管比较理想的段与段之间延期时间间隔;4)实际爆破过程中,雷管延时误差是普遍存在的,总体误差呈现为正值。 相似文献
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简要介绍内燃机电站行业国际标准的制修订动态及ISO8528-1的部分修订内容,并提出贯彻实施意见。 相似文献
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以常见的机械磨损故障——气门间隙过大故障为例进行了试验研究,提取缸盖振动加速度信号进行分析,发现故障状态的时域信号有明显低频周期性冲击,但在频谱的低频区间未现冲击频率;同时,在故障状态频谱中,3 000~4 500Hz范围的高频段振动能量有显著增加。通过小波包分解方法对信号分解至该故障特征频段,再进行希尔伯特解调分析,解调谱现显著的对应低频冲击的频率成分,可作为故障识别特征。分析结果表明,气门间隙过大故障造成的冲击引起缸盖或其部件共振调制现象,综合运用上述时域、频谱和共振解调分析,可对配气机构磨损故障进行故障特征提取,从而为准确诊断故障提供依据。 相似文献
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J. T. Song S. J. Ahn W. B. Jeong W. S. Yoo 《International Journal of Automotive Technology》2017,18(2):293-300
Idle vibration, occurring when a vehicle comes to a stop while the engine is on, is known to be a main cause of discomfort for passengers, and the customer effect has been recently growing. The frequency of idle vibration is determined by the engine type. To lower the vibration, various technologies have been applied to optimize the engine mount and vehicle body structure. In addition to the technological developments, research on human response with a consideration of idle vibration is needed to effectively reduce the level of discomfort experienced by passengers. Seats aimed at enhancing static comfort influence the sitting posture of passengers; sitting posture is a factor affecting human body characteristics that response to idle vibration. This study examined the absolute discomfort threshold of idle vibration according to the sitting postures of 13 taxi drivers. The four sitting postures of subjects on a rigid-body seat without a backrest were variables in the determination of absolute discomfort threshold of idle vibration. The absolute discomfort threshold curves obtained in this experiment were less sensitive to frequency changes than the frequency weighting function of ISO 2631-1. 相似文献
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为评价在生产常规作业阶段爆破施工方式对隧道结构的影响,对宋家湾隧道爆破振动进行监测,以获取主振频率,最终以频率和振动速度2个指标评估隧道爆破作业振动效应.本次爆破的最大振动速度为3.1 cm/s,主振频率范围为27.34~70.31 Hz,最大振动速度远小于国家标准.可知对隧道支护结构影响有限频率范围为27.34~70.31 Hz,远高于隧道的自振频率(一般在3~9 Hz范围内),不会出现共振放大现象. 相似文献