盘式制动系统模态实验探究

本文研究盘式制动系统模态特性,通过实验测试和有限元分析得到制动盘自由和耦合振动模态,验证对称结构振动的正弦和余弦模态假设,提供环形梁简化模型的分析依据,比较摩擦块与制动盘耦合振动和制动盘自由振动的异同.动态测试得到耦合系统的位移响应.     

盘式制动系统模态实验探究

本文研究盘式制动系统模态特性，通过实验测试和有限元分析得到制动盘自由和耦合振动模态，验证对称结构振动的正弦和余弦模态假设，提供环形梁简化模型的分析依据，比较摩擦块与制动盘耦合振动和制动盘自由振动的异同。动态测试得到耦合系统的位移响应。     

电磁铁力特性测试系统的研究

鉴于力特性是表征电磁铁性能的基本特性,基于力传感器和位移传感器等器件,提出了一种电磁铁力特性测试系统,介绍了其结构及原理,建立了测试系统模型,对测试系统误差进行了分析.通过试验研究了测试系统的动态系统误差,并对单向和双向两种特定结构的比例电磁铁的静动态力特性进行了测试.试验结果表明:该系统测试方便、测试结果准确可靠,适用于单向和双向电磁铁静动态力特性的测试.     

二轴数控工作平台的建模与仿真研究

利用系统建模与仿真的方法对数控机床的X-Y工作平台进行研究，建立了数控机床伺服系统动态性能的仿真模型，分析了伺服系统动态特性，应用ADAMS和Matlab/Simulink软件实现对整个系统的动态性能仿真，由伺服系统的Bode图和阶跃响应可以求出伺服系统的各项性能指标，具有很好的动态响应特性，可迅速地为数控机床伺服系统的调试提供可靠依据。     

螺旋槽型干气密封系统轴向工作模态研究

干气密封系统的轴向动态特性会影响密封气膜的密封特性,从而影响机械密封的稳定性和可靠性,采用高灵敏加速度传感器和数据采集装置,设计螺旋槽型干气密封装置轴向振动测试试验,采用半互功率谱密度函数实现对干气密封装置的工作状态模态分析,分别利用平均相位偏差、模态相位线性度、模态复杂性和模态指示函数4个数学指标对模态参数辨识结果进行验证,结果表明:半互功率谱密度函数的模态分析验证结果较好,适用于干气密封组合型装置的环境激励工作状态模态分析。     

基于虚拟仪器试验系统的电子机柜模态试验

根据电子机柜模态试验的特点,在LabVIEW平台上开发出一套集数据采集、分析和参数识别为一体的虚拟仪器测试系统(VITS).通过与传统的测试仪器的测试结果比较表明,该测试系统能够实现对模态参数的计算和分析,计算结果准确,效率较高,满足电子机柜模态试验的要求.运用该虚拟仪器系统对电子机柜进行模态试验,获得其各阶固有频率.     

压电加速度计在水工闸门模态测试中的应用

为了用试验法研究某水工闸门的振动特性,在分析压电加速度计性能指标的基础之上,针对某水利枢纽上的平面闸门,选用HK9104型压电加速度计,设计测试系统,运用脉冲锤击法进行模态测试,通过模态分析得到闸门结构的模态振型和模态参数.结果表明:闸门的固有频率以低频为主,分布在较宽范围内,这是引起流激振动的主要内因,压电加速度计具有较好的低频响应特性和较高的灵敏度.     

失重环境下可控柔性臂的模态特性

在非重力场中,考虑控制器动态反馈的影响,对存在控制器定位约束的柔性臂系统进行动力分析,研 究其在相对平衡位置的模态特性．以具有柔性关节和弹性臂杆的可控柔性臂为研究对象,分析了控制器作用下的反 馈约束特性,将控制器位置和速度增益引入力边界条件,得到了耦合控制器参量的模态特征方程,证明了反馈约束 的存在使得系统特征频率为复频率,且模态主振型是复变函数．通过数值仿真,明确了可控柔性臂的模态特性与控 制器增益之间的关系,得到了不同于经典振动理论的结论．设计了可控柔性臂的仿失重实验平台,试验模态结果证 明了理论分析的有效性．     

激光印字机模态试验与分析

本文针对非击打式打印机──激光印字机的整机及关键部件的动态特性参数进行了测试，建立了一套实验系统，开发了一套DSP的硬件与软件。获得了系统模态参数数据并对它进行分析，找出它的薄弱环节。     

VXI-640 GVT测试系统及工程应用

VXI-640 GVT系统是以当前国际上先进的VXI总线技术为平台而研制成功的国内较大规模的全机地面振动试验系统,该系统由Agilent VⅪ数据采集前端和MTSI-DEAS Test模态测试分析软件,并配以自行研制的纯模态软件组成.介绍了VXI-640系统的主要组成及系统特点,该系统已成功地应用于飞机振动试验和其他结构的振动测试.     

摩托车车架动特性计算机仿真分析

摩托车车架的动特性是摩托车振动舒适忡的一个重要影响因素,采用计算机仿真分析方法进行摩托车车架动特性分析能有效的减少试验费用,缩短产品开发周期。该文基于某摩托车车架的二维图纸和实物,首先利用UG软件进行几何建模;然后用MSC．PATRAN／NASTRAN软件建立其有限元模型,并进行了自由模态的计算机仿真分析;最后利用LMS实验模态分析系统对该车架进行了实验模态分析,验证了计算机仿真结果,结果表明仿真精度较高,可将二者相结合以分析车架的振动特性。     

大型立式玻璃磨边机整机动态特性分析

大型立式玻璃磨边机的动态特性影响玻璃磨边质量和磨边效率。利用Solidworks软件建立某大型立式玻璃磨边机三维实体模型,导入ANSYS软件中,对整机结构有限元动力学分析,得到该磨边机前六阶模态参数,分析了各阶振型对磨边机动态特性的影响,为磨边机结构的改进设计提供了理论依据。     

基于dyna971的数控镗铣机床动态模拟仿真

落地式数控镗铣机床结构复杂,为保证机床具有良好的动态性能,在开发设计该类机床时要进行整机的动态模拟仿真分析。针对这一要求,提出一种实际设计中实用化程度较高的机床动态模拟仿真思路,首先对数控落地镗铣机床样机进行模态试验,获取床身〖CD*2〗滑座、滑座〖CD*2〗立柱、立柱〖CD*2〗主轴箱等结合面的模态参数,在对模态参数进行有限元方法优化识别后,利用COMBIN14单元模拟优化后的结合部参数建立机床整机有限元模型。在dyna971软件平台对整机有限元模型进行动态模拟仿真,从模拟仿真分析结果可以看出机床在受到外界作用力时,其输出的应力和应变变化波形平稳,说明经过上述分析而设计出的机床具有良好的动态性能。目前,该研究成果已应用于此类型机床的批量生产。     

A multi-purpose tool for dynamic simulation of paper mills

A simulation environment for the dynamic simulation of paper or board mills has been developed. APMS (advanced paper mill simulator) provides tools for fast and easy modelling of the plant comprising e.g. stock preparation, approach system, wet end and dry end of the machine. The models are based on the first principles of physics and chemistry whenever it is possible. This mechanistic modelling principle with efficient equation solution techniques ensures fast and accurate simulation for the purposes of process and automation design, analysis and operator training.     

Dynamic response analysis of linear structural systems subject to component changes

A method of analysis is developed for determining transient responses of large multiply-connected structural systems subjected to changes of structural components. A dynamic system is divided into two subsystems: the support which remains unaltered and the branch which is liable to change. The response characteristics of an original system are used as a basis for evaluating the new response of the altered system. The responses of the support interface coordinates due to external excitations on it are called base motion. The equations of motion of the system are formulated using subsystem modal properties such that the base motions are the generalized forcing functions. This enables incorporation of the alternative properties in the new analysis without having recourse to the entire system modal properties. The method is applied to a 16-storey building rigid frame model. The methods gives response results comparable with the conventional integrated system analysis. Approximations due to modal truncation are the same as component mode substitution method.     

Modelling the dynamics of industrial robots for milling operations

Using industrial robots as machine tools is targeted by many industries for their lower cost and larger workspace. Nevertheless, performance of industrial robots is limited due to their mechanical structure involving rotational joints with a lower stiffness. As a consequence, vibration instabilities, known as chatter, are more likely to appear in industrial robots than in conventional machine tools. Commonly, chatter is avoided by using stability lobe diagrams to determine the stable combinations of axial depth of cut and spindle speed. Although the computation of stability lobes in conventional machine tools is a well-studied subject, developing them in robotic milling is challenging because of the lack of accurate multi-body dynamics models involving joint compliance able of predicting the posture-dependent dynamics of the robot. In this paper, two multi-body dynamics models of articulated industrial robots suitable for machining applications are presented. The link and rotor inertias along with the joint stiffness and damping parameters of the developed models are identified using a combination of multiple-input multiple-output identification approach, computer-aided design model of the robot, and experimental modal analysis. The performance of the developed models in predicting posture-dependent dynamics of a KUKA KR90 R3100 robotic arm is studied experimentally.     

Object-oriented design support system for machine tools

This paper deals with an object-oriented intelligent design support system which is intended to assist in the basic design of machine tools, in particular machining centres. The machine tools design process is analysed through interviews with experienced designers, and an object-oriented model is established to represent the design process. Software modules named design objects are proposed, which are basic components for the implementation of an intelligent design support system for machine tools. A prototype of the design support system for machining centres is developed based on the design objects, and some case studies are carried out to verify the effectiveness of the methods proposed.     

弹性支撑下风电机组传动系统结构动力分析

考虑水平轴风力发电机组齿轮箱弹性支撑的柔性连接特性,基于集中质量思想和拉格朗日方法,建立风力发电机传动系统多体动力学模型,研究了齿轮箱弹性支撑对传动系统结构动力学特性的影响.利用动力学模型和模态分析方法,得到了由弹性支撑耦合到系统后的模态频率,并获取了在该模态激励下的模态动能分布.采用变参数方法进行传动系统模态对齿轮箱弹性支撑刚度变化的敏感性分析,利用模态叠加法进行齿轮箱体的动响应分析.数值求解结果和分析表明,考虑齿轮箱弹性支撑的传动系统某阶固有频率即为弹性支撑下齿轮箱体振动主模态;弹性支撑线刚度对传动系统低频率固有模态存在一定影响;齿轮箱体振动分析时应考虑1阶和2阶的低频模态较为合理.本研究工作对传动链系统方案可靠性设计和抑制传动链振动的加阻控制提供了一定理论基础.     

基于AT89C55单片机的数控机床远程测控仪的研制

研制了一种基于AT89C55单片机的数控机床远程测控仪,主要介绍了该测试仪的硬件和软件设计,详述了数控机床远程测控的基本原理,并在数控机床远程控制平台上进行了直线插补和圆弧插补等插补精度的实时远程测试和误差分析。该测试仪已在多家单位生产实践中应用,测试效果良好。