基于DASP的变速箱壳体振动模态试验与分析

通过进行变速箱壳体振动模态试验,客观地分析了变速箱壳体的振动状态。采用DASP(Data AcquisitionSignal Processing)软件对HW25505TCL型铝合金变速箱壳体进行振动模态试验。利用特征系统实现(ERA)法进行模态参数辨识,并与复频域最小二乘法(PloyLSCF)法对比,得到可靠的1~4阶频率和阻尼,并由此进行振型分析。采用振型相关矩阵进行模态验证,通过与计算模态比较,证明两者的有效性和可靠性。将DASP应用变速箱壳体振动模态试验,不仅获得变速箱壳体高阶频率、阻尼及振型,还可解决类似壳体的振动问题,为进一步改进变速箱壳体的结构特性以及基于模态分析的变速箱壳体故障诊断等提供了理论依据。     

某型汽车变速箱的振动噪声分析

针对某型新能源车用两挡变速箱的振动噪声问题,通过NVH试验、理论计算、仿真分析相结合的方法分析引起振动噪声的根源。首先,基于整车NVH主观评价的结果,通过NVH试验采集变速箱振动信号并进行数据处理分析;其次,通过计算变速箱各齿轮副啮合频率及特征阶次,判断各阶噪声的产生位置;最后,使用ANSYS WORKBENCH软件对变速箱壳体进行模态分析进而得出前20阶固有频率,结合试验数据及啮合频率判断产生各阶噪声的共振频率点。基于对变速箱振动噪声的分析,为下一步制定整改措施提供了必要条件。     

汽车变速箱的振动特性与模态联合分析研究

某型号汽车变速箱存在箱体开裂的问题,为了对某型号汽车变速箱进行结构优化与精确模态分析研究,以该型号汽车变速箱箱体为研究对象,先对其振动特性进行了研究,获得了箱体动态响应的最佳激励方向和频带区域,了解了变速箱箱体的内在特性,然后采用有限元分析与试验模态分析相结合的方式,对变速箱箱体进行了模态分析,将所得数据进行对比后,分析了变速箱箱体开裂原因,为后续对该型号汽车变速箱进行结构优化奠定了基础。     

某轻卡动力总成的结构动力学分析

某轻卡变速箱壳体在使用寿命内出现不同程度上的开裂问题,对某轻卡动力总成进行了有限元模态分析和试验模态分析。通过分析对比结果,验证了两者的有效性和正确性。分析了变速箱壳体振动的敏感部位和开裂原因,为结构动力学修改提供理论依据。     

基于PSD的某轻卡汽车变速箱振动噪声特性分析

针对某轻卡变速箱的工作特点,对该变速箱的空挡、5个前进挡和1个倒挡的升速过程、稳态运行以及降速过程进行振动与噪声测试,并对振动信号进行时域和频域分析。分析结果对于了解齿轮变速箱的振动与噪声特性以及基于振动和噪声信号的齿轮箱质量评价具有重要意义,并且为以减振降噪为目的的齿轮箱结构动力学优化设计,准备了基础数据及分析方法。     

奥托汽车变速箱箱体有限元模态分析

汽车变速箱是一个多自由度弹性振动系统,作用于该系统的各种激振力使变速箱产生复杂振动,其必然带来整车的振动和噪声,影响汽车乘坐舒适性.本文以奥托汽车变速箱为研究对象,基于SolidWorks建立奥托汽车变速箱的三维实体模型,并应用COSMOSWorks有限元分析软件建立变速箱箱体的有限元模型,完成了该汽车变速器箱体的模态分析,分析结果可为寻找变速箱箱体产生振动的敏感部位和箱体的结构设计提供依据.     

某轻卡变速箱发动机及车架模态测试与分析

采用锤击模态测试方法对发动机、变速箱及车架模态进行了测试,并获得模态参数。通过对截取的空车搓板路上各测点振动信号以及空车在障碍路上工作时各测点振动信号进行工作模态测试分析,获知轻卡在空载工作环境中的各阶工作模态参数。最后,对试验结果进行了总结分析,发现几个较为敏感的模态频率。为下一步从完整的动态特性方面分析判断发动机、变速箱及车架破损的根本原因,提供理论及技术支持。     

变速箱振动与噪声分析

分析了某变速箱试验时的异常振动和噪声原因。先对一台样机测试其各挡稳定过程的振动和噪声信号,再对测得的信号进行功率谱密度分析。之后,运用Pro/Engineer建立了变速箱壳体的实体模型,并用OptiStruct软件进行了壳体前端面加零位移约束的模态分析;计算了各挡齿轮的啮合频率,分析了壳体的模态频率与齿轮啮合频率对振动和噪声信号功率谱中峰值的影响。最后根据分析结果,提出对壳体的改进建议,以达到变速箱减振降噪的目的。     

重型汽车变速箱箱体有限元模态分析

变速箱是汽车传动系统的主要部件之一,它的振动必然带来汽车整车的振动和噪音,影响汽车的整车性能。以重型汽车变速箱箱体为研究对象,应用PRO/E软件建立箱体的三维实体模型,并利用ANSYS软件建立箱体的有限元模型,完成了箱体的有限元模态分析。分析结果可为寻找变速箱箱体产生振动的敏感部位和箱体的结构优化设计提供依据。     

基于UG技术的采棉机变速箱体的模态分析

为优化采棉机变速箱体的振动特性，首先建立起一简化力学模型，并由力和力矩的平衡方程推导出采棉机变速箱体的振动微分方程；借助UG平台，通过对三维模型进行整体分析，理想化模型后去掉细小特征，网格划分后得到有限元模型，载荷施加、约束确定后得到仿真模型，最终求解得到变速箱体的模态参数和振型云图；最后通过对仿真结果的分析，阐述了变速箱体的薄弱结构以及不同频率对变速箱体振动变形的影响，为箱体的动力学优化提供了理论依据。     

基于边界元理论的鼓风机组管路振动噪声控制研究

针对鼓风机组管路振动噪声问题,应用结构声辐射理论和结构振动测量数据分析振动声辐射强度。以实测振动信号为依据,根据对低频段计算精度较好的边界元理论,应用有限元软件和Sysnoise声学仿真软件建立了实际声场的边界元流体模型和有限元结构模型的耦合模型,得到了模拟声场的仿真结果,并与实测结果进行比较,确定了主要噪声能量来源于管路振动造成的结构振动。通过分析振动的来源以及振动传递的路径和传递特性,确定了隔振降噪的方法。依据理论分析结果,对实际现场采取了有效的隔振降噪方法,隔振后降噪效果明显。     

汽车变速箱齿轮系统噪声计算方法的研究

针对汽车变速箱齿轮系统工作时的噪声问题,提出了一种定量计算变速箱齿轮系统噪声的方法,求解了该系统的振动方程,并利用Kato方程量化了变速箱齿轮系统的噪声主要来源,重点研究了在不同声源辐射模型下变速箱齿轮系统噪声的声功率大小。试验证明,该方法可较准确地对变速箱齿轮系统所产生振动噪声进行定量计算,为变速箱齿轮系统的降噪及优化设计提供了依据。     

重卡传动系统扭转共振计算模拟与两段式减振阻尼器的设计

基于重型汽车降低振动、减少噪声的要求,研发了一种两段式减振阻尼器的设计方法,采用扭转振动理论建立了重型汽车传动系统的振动方程,运用matlab软件建立16自由度的重卡传动系的振动数模,得出发生扭转共振的的自然频率,模态及频域分析。模拟示笵得到6汽缸发动机3阶激励产生在飞轮,变速箱及车桥的扭转角或扭转力矩与发动机转速的函数关系、分析也提供传动系自然频率和减振器弹簧刚度或变速箱速比间的函数关系以及振动性能与减振器的阻尼力矩的函数关系。结果表明:有效的两段式阻尼器设计能起到降振减噪的作用。     

双离合变速器敲击噪声的仿真分析与实验评价

针对某变速器在车辆一挡起步工况实验中出现敲击噪声的问题,利用LMS Virtual.Lab软件搭建了包含轴、齿轮、同步器、轴承、差速器、壳体等部件的双离合变速器刚柔耦合模型.考虑输入轴转速波动、轴承刚度非线性、齿轮啮合时变刚度和阻滞力矩,以再现敲击噪声发生时壳体的振动响应.仿真计算与实验结果的良好一致性,验证了仿真分析方法的有效性.     

Effects of macro-parameters on vibration and radiation noise for high speed wheel gear transmission in electric vehicles

Considering flexible shafts, a coupled dynamic model for the gear transmission system of wheel reducer used in electric vehicle was developed. By combining the acoustics finite element modal for housing in Virtual Lab and the coupled dynamic model for gear transmission system, a simulation method was proposed for the prediction of the radiation noise for the wheel reducer. Then, the effects of different macro geometry gear parameters including pressure angle and helical angle on the dynamic response and radiation noise were investigated under the rated working condition. Results show that the peak-peak value of the transmission error dramatically falls in the starting zone, followed by an upward trend with the increase of the pressure angle for the low speed stage gear pair. The minimum transmission error and vibration acceleration occur when the pressure angle is 17°. The increase of the pressure angle does not affect the sound pressure level at the field point obviously. The design case with 17° pressure angle shows the optimum radiation noise level, which is 4.41dB less than the original model. Compared to the pressure angle, the helix angle has a major influence on the transmission error, vibration acceleration and acoustic radiation noise. With the increase of the helix angle, the time-varying transmission error curve becomes more smooth with a lower peak-peak value. Besides, the increase of helix angle results in lowering the varying and fluctuating trend of both vibration acceleration and acoustic radiation noise. The design case with 24° helix angle shows the prime radiation noise level, which is 7 dB less than the original scheme.     

Interior noise analysis of a construction equipment cabin based on airborne and structure-borne noise predictions

Noise from construction equipment affects not only surrounding residents, but also the operators of the machines. Noise that affects drivers must be evaluated during the preliminary design stage. This paper suggests an interior noise analysis procedure for construction equipment cabins. The analysis procedure, which can be used in the preliminary design stage, was investigated for airborne and structure-borne noise. The total interior noise of a cabin was predicted from the airborne noise analysis and structure-borne noise analysis. The analysis procedure consists of four steps: modeling, vibration analysis, acoustic analysis and total interior noise analysis. A mesh model of a cabin for numerical analysis was made at the modeling step. At the vibration analysis step, the mesh model was verified and modal analysis and frequency response analysis are performed. At the acoustic analysis step, the vibration results from the vibration analysis step were used as initial values for radiated noise analysis and noise reduction analysis. Finally, the total cabin interior noise was predicted using the acoustic results from the acoustic analysis step. Each step was applied to a cabin of a middle-sized excavator and verified by comparison with measured data. The cabin interior noise of a middle-sized wheel loader and a large-sized forklift were predicted using the analysis procedure of the four steps and were compared with measured data. The interior noise analysis procedure of construction equipment cabins is expected to be used during the preliminary design stage.     

齿轮传动振动噪声计算的Kato方法

建立了齿轮传动的时变动力学模型，分析了啮合刚度，传动误差对振动响应的影响，在此基础上，将齿轮传动啮合分成单齿啮合区，采用Kato方法对振动产生的噪声进行了定量计算，得出了双齿啮合区内辐射噪声大于单齿啮合区，并给出了每一啮合时刻辐射噪声大小，研究表明该方法可以较好地对齿轮振动所产生的噪声进行定量计算，为齿轮系统的降噪设计奠定了基础。     

汽车变速器降噪分析及控制方法研究

汽车结构振动噪声及舒适性已成为评价动力机械产品的重要指标,变速器是汽车传动系统的主要构成部分,变速器的噪声和振动对性能对提高整车的NVH性能极其重要.对变速器的主被动降噪设计进行分析,为国内汽车工程领域提高变速器的NVH性能提供一定的信息和指导.     

The noise reduction of a DC motor using multi-body dynamics

The DC motor of a vehicle may cause noise and vibration due to high-speed revolution, which can make a driver feel uncomfortable There have been various studies attempting to solve these problems, mostly focusing on the causes of noise and vibration and a means of preventing them The CAE methodology is more efficient than a real test for the purpose of looking for various design parameters to reduce the noise and vibration of the DC motor In this study, a design process for reducing brush noise is presented with the use of a computer model, which is made by using a multi-body dynamics program (DADS) The design parameters to reduce the brush noise and vibration were proposed using a computer model They were used to reduce the noise and vibration of the DC motor and verified by the test tesults of the fan DC motor in the vehicle This method may be applicable to various DC motors     

基于刚柔耦合的行星齿轮减速器减振降噪研究

针对某精密行星齿轮减速器的振动噪声问题,通过Romax Designer软件建立刚柔耦合动力学模型;并对减速器箱体进行模态分析,提取箱体的前六阶约束模态振型和固有频率,确定产生噪声的共振频率点;同时分析了齿轮传动误差、齿轮时变啮合刚度等激励的特性。提出通过齿轮修形降低减速器内部动态激励进而减小振动和噪声的方法,并使用LMS Virtual.lab软件对减速器进行声学响应求解。仿真结果表明,优化后减速器的振动和噪声明显降低;最后搭建了行星齿轮减速器试验台,实测噪声与仿真结果基本吻合,验证了该方法的合理性。