滚轮传动机构辐射噪声预测研究

发布时间：2018-03-31 01:15

本文选题：滚轮传动　切入点：噪声辐射模型　出处：《江苏大学》2017年硕士论文

【摘要】：滚轮传动机构被广泛运用于工业生产当中,然而其在滚轮传动过程会产生极大的振动噪声污染,这不仅对工作人员的身心健康和工作态度起到一定的负面影响,更会约束生产力的提高。本文结合了试验与仿真来预测滚轮传动机构的噪声值,最终得到了一种较为准确的噪声预测方法。本文的主要工作如下:首先,本文结合国家标准提出了一套振动噪声试验方案,选定振动信号与噪声信号的测量位置。试验时采集了滚轮传动机构在各稳态工况下以及匀加速工况下的振动和噪声信号,再通过分析振动和噪声信号研究其振动噪声特性。其次,通过滚轮间的受力分析情况,确定了滚轮传动机构的振动响应主要是由垂直方向的受力引起的。运用集中参数法建立滚轮传动机构垂直方向的力学模型,并依照力学模型建立振动微分方程,通过实际测量和计算,确定了滚轮传动机构的各个集中质量、集中刚度、集中阻尼等相关参数。然后求解出未知量仅为激励力的振动速度响应式。接着,根据实际测量尺寸在CATIA里建立滚轮传动机构的结构模型,利用Hypermesh软件对其进行网格处理,从而建立了滚轮传动机构的有限元模型。然后再将其导入有限元分析软件中,进行结构模态分析。并根据有限元分析软件中的激励力识别逆运算法功能,导入测得的结构上部分位置的振动加速度频谱后,可以计算出选取的等效激励点处的激励力。再将激励力带入之前计算的振动响应式中,求解出每个集中质量的振动速度响应。最后,基于点声源、线声源的声辐射公式建立了滚轮传动机构的声辐射模型,将整个滚轮传动机构的噪声辐射等效为一个线声源和20个点声源的声辐射的叠加。将各点声源、线声源的振动速度以及结构实际尺寸带入声辐射模型,计算出滚轮传动机构辐射声场中对应试验测量点的声压级值,并与试验中测得的该处实际声压级进行对比。根据对比结果对模型进行优化和修正,从而得到了一种较为精确的滚轮传动机构的噪声辐射预测方法。
[Abstract]:Roller drive mechanism is widely used in industrial production, however, it will produce great vibration and noise pollution in the process of roller transmission, which not only has a certain negative impact on the physical and mental health and working attitude of the staff.It will restrain the increase of productivity.This paper combines experiment and simulation to predict the noise value of roller drive mechanism, and finally a more accurate noise prediction method is obtained.The main work of this paper is as follows: firstly, a set of vibration and noise test scheme is proposed according to the national standard, and the measuring position of vibration signal and noise signal is selected.The vibration and noise signals of roller drive mechanism under steady state and uniform acceleration are collected during the test. The vibration and noise characteristics of roller drive mechanism are studied by analyzing the vibration and noise signals.Secondly, through the analysis of the force between the rollers, it is determined that the vibration response of the roller drive mechanism is mainly caused by the vertical force.The mechanical model of roller drive mechanism in vertical direction is established by means of lumped parameter method, and the vibration differential equation is established according to the mechanical model. Through actual measurement and calculation, the concentrated mass and stiffness of roller drive mechanism are determined.Concentrated damping and other related parameters.Then the vibration velocity response formula with unknown quantity is obtained.Then, according to the actual measurement size, the structural model of the roller drive mechanism is established in CATIA, and the finite element model of the roller drive mechanism is established by using the Hypermesh software to mesh it.Then it is introduced into the finite element analysis software for structural modal analysis.According to the function of the inverse calculation method of force identification in the finite element analysis software, the excitation force at the selected equivalent excitation point can be calculated after introducing the vibration acceleration spectrum of the measured part of the structure.Then the excitation force is introduced into the previously calculated vibration response formula, and the vibration velocity response of each lumped mass is solved.Finally, based on the sound radiation formula of point source and line sound source, the sound radiation model of roller drive mechanism is established. The noise radiation of the whole rolling wheel transmission mechanism is equivalent to the superposition of one line sound source and 20 point sound sources.The vibration velocity of each point source and line sound source as well as the actual size of the structure are brought into the sound radiation model to calculate the sound pressure level of the corresponding test point in the radiation sound field of the roller drive mechanism, and to compare the actual sound pressure level with the actual sound pressure level measured in the test.According to the comparison results, the model is optimized and modified, and a more accurate prediction method of the noise radiation of the roller drive mechanism is obtained.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH132;TB533.1

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