基于ADAMS的含间隙柔性酒瓶装箱机构的优化设计与动力学仿真

基于ADAMS仿真软件平台,对酒瓶装箱机构进行了建模仿真,并以抓头加速度最小为目标函数对机构进行了结构优化。基于间隙矢量模型,考虑运动副间隙和杆件柔性的影响对酒瓶装箱机构重建模型,并基于非线性碰撞接触力模型建立了构件接触处的碰撞接触力与位移关系,得到了运动副间隙和杆件柔性对机构运动特性及动力学特性的影响规律。结果表明:当同时考虑运动副间隙和连杆柔性时,柔性杆对轴销和轴套的碰撞有一定的缓冲作用,从一定程度上消减了运动副间隙对目标点运动特性的不利影响。     

含间隙柔性曲柄摇杆机构动力学分析

基于ADAMS(automatic dynamic analysis of mechanical system)的仿真软件平台,采用冲击函理论模拟间隙接触的碰撞,研究含间隙运动副柔性曲柄摇杆机构的动力学行为.轴与轴套间旋转间隙铰有三种运动状态,自由运动、碰撞和连续接触.文中主要对比刚性连杆和柔性连杆对机构运动性能的影响,考虑柔性时,应用Ansys软件取连杆的前三阶模态生成中性文件导入ADAMS进行仿真.结果显示,柔性杆对运动副接触的碰撞力有缓冲作用,同时与理想运动副状态十分接近.     

考虑磨损含间隙曲柄滑块机构的动态特性研究

为得到准确的含间隙铰接机构的接触碰撞模型,在ADAMS中建立含间隙的曲柄滑块机构,以含间隙曲柄滑块机构运动副为对象分析其在考虑磨损情况下的动态特性。以接触一碰撞模型为基础,采用非线性等效弹簧阻尼模型,将用MATLAB处理过的数据和磨损函数嵌入到ADAMS模型中进行动力学仿真,并将得到的动态特性曲线进行分析。结果表明：磨损对间隙运动副的速度、加速度、接触碰撞力和力矩有很大的影响,同时,此种建模方法对建立准确的含间隙机构的模型有很大的参考意义。     

考虑双间隙曲柄滑块机构动力学建模与分析

以曲柄滑块机构为例,考虑机构两处旋转副间隙,引入平面多体系统中转动副间隙描述的数学模型,采用修正混合非线性弹簧阻尼接触碰撞力模型分析运动副元素的碰撞特性,采用牛顿-欧拉法建立了曲柄滑块机构的运动学和动力学模型,使用数值仿真和ADAMS仿真分析对比其仿真结果,验证所建立模型的正确性,得出运动副间隙对机构动力学特性的影响特点。     

含非规则粗糙间隙表面铰链关节的平面柔性多连杆传动系统动态误差与运动副磨损周期行为分析

传统旋转间隙关节接触模型假定销轴和衬套接触面形状是规则的并忽略了磨损效应的影响,降低了机构动力学模型预测精度。提出了一种含非规则粗糙间隙表面铰链关节的平面柔性多连杆机构多体动力学建模、磨损预测和动态误差分析方法。为准确描述运动副元素间碰撞行为,考虑滑动轴承间隙关节的磨损效应,提出了一种非规则粗糙间隙表面铰链关节的改进接触模型。在此基础上,考虑柔性杆的影响,基于绝对节点坐标法建立了含非规则粗糙间隙表面铰链关节的平面柔性多连杆传动系统多体动力学模型。与基于传统光滑间隙模型的结果相比,基于非规则粗糙间隙改进模型的多连杆机构动态响应更接近于试验值,验证了所提出计算方法的有效性。仿真结果表明,选用CuSn10P和CuPb30作为铰链衬套材料能够有效降低多连杆机构滑块动态响应偏差和提高机构的运动精度;表面粗糙度过高会导致运动副磨损加剧,过低则会降低间隙表面微凸体对碰撞能量的吸收。此外,磨损加剧了间隙表面轮廓不规则度,导致机构动态响应的不稳定性增大,运动精度降低。     

含间隙卫星天线双轴机构动态磨损特性研究

卫星天线双轴驱动机构是天线系统实现精确定位的关键组件,磨损间隙是影响天线指向精度及寿命的主要因素.采用非线性弹簧阻尼模型建立了间隙处的接触碰撞模型,同时采用Coulomb摩擦模型考虑运动副间隙处的摩擦作用,进而建立了含间隙双轴机构的动力学模型,对其进行动力学仿真,提取出接触碰撞时的动力学参数,基于Archard's摩损模型计算运动副间隙的动态磨损量,从而得到间隙运动副的动态磨损特性,为进一步研究非规则时变间隙对卫星天线系统动态性能的影响提供基础.     

基于Pro／E、ANSYS和ADAMS的动力学联合仿真研究

阐述了用三维CAD绘图软件Pro/Engineer、有限元软件ANSYS、多体动力学仿真软件MSC.ADAMS联合仿真的关键技术;建立了考虑连杆柔性和运动副粘性摩擦的曲柄滑块机构的虚拟样机模型,对其进行动力学仿真,验证了连杆柔性和运动副粘性摩擦使得曲柄响应速度变慢.     

含间隙曲柄滑块机构运动副动态磨损研究

含间隙曲柄滑块机构中运动副的润滑情况不同于滑动轴承,其相对速度不足以形成动压润滑而处于边界润滑状态下.为了分析此状态下的动态磨损问题,考虑到含间隙运动副边界润滑时轴套的切向弹性变形和切向阻尼,结合考虑间隙运动副碰撞接触的非线性弹簧阻尼模型,提出边界润滑条件下的间隙副接触力模型,进而在此基础上推导出间隙副的动态磨损模型,并对含间隙曲柄滑块机构的运动副动态磨损进行数值分析.计算结果表明副元素间呈现出连续弹性变形现象,在连续变形接触处,动态磨损量较大使磨损加剧,并出现非均匀磨损.     

间隙对平面机构运动特性的影响分析

由于装配、制造误差和磨损,运动副中的间隙是不可避免的,在机构运行期间,间隙使实际机构与理想机构的运动发生偏离,降低了机构运动精度。以含间隙曲柄摇杆机构为研究对象,建立了系统的动力学方程,并基于ADAMS进行了动力学仿真,仿真计算结果能够准确的预测含间隙机构的运动特性;利用ADAMS软件进行动力学仿真分析,可以提高效率,降低成本。     

基于ADAMS的往复发动机敲缸故障仿真研究

基于多刚体系统动力学方法和非线性弹簧阻尼接触模型,在ADAMS中对含活塞-缸壁间磨损间隙的曲柄滑块机构进行动力学建模及动态仿真.研究该机构在考虑外载荷、构件惯性力、重力、材料接触刚度及阻尼等条件存在时,不同程度磨损下的活塞接触动力学响应,计算并比较了磨损间隙条件下的活塞侧推力、拍击力及活塞2阶运动特性参数等数据;阐明了运动副间隙引起活塞敲缸现象的发生机理.该工作为内燃机配缸间隙的选择、磨损间隙的故障诊断及振动控制提供了参考依据.     

Investigations on the dynamic characteristics of a planar slider-crank mechanism for a high-speed press system that considers joint clearance

Clearances in the joints of mechanisms are unavoidable because of numerous uncertainties, such as manufacturing tolerances, assembly processes, and progressing wear. The dynamic characteristics of a planar slider-crank mechanism, including clearance joint and balancing mechanism, are investigated in this study using a computational method. A suitable model is built using the simulation software ADAMS, in which actual features, such as contact and friction, are considered. A contact-impact model that incorporates the IMPACT function and that considers energy loss in the contact process, is also built. The experimental platform is established and acceleration experiments on the mechanical system at different driving speeds are conducted. Obtained tests results demonstrate that the dynamic response of a multibody mechanical system can be effectively predicted using the proposed method. Furthermore, the effects of the driving speed of the crank shaft, the size of the joint clearance, and the balancing mechanism on the dynamic characteristics of the mechanism are studied.     

Dynamic analysis of planar mechanical systems with clearance joints using a new nonlinear contact force model

We investigated the dynamic behavior of planar mechanical systems with clearance joints. First, the contact effect in clearance joint was studied using a new nonlinear contact force model, and the rationality of this model was verified by the results of numerical simulations, which are based on a journal and bearing contact model. Then, the dynamic characteristics of a planar slider-crank mechanism with clearance were analyzed based on the new nonlinear contact force model, and the friction effect of clearance joint was also considered using modified Coulomb friction model. Finally, the numerical results of the influence of clearance size on the acceleration of slider are presented, and compared with the published experimental results. The numerical and experimental results show that the new nonlinear contact force model presented in this paper is an effective method to predict the dynamic behavior of planar mechanical system with clearance joints, and appears to be suitable for a wide range of impact situations, especially with low coefficient of restitution.     

Prediction of vibration characteristics of a planar mechanism having imperfect joints using neural network

Clearance is inevitable in the joints of mechanisms due primarily to the design, manufacturing and assembly processes or a wear effect. Excessive value of joint clearance plays a crucial role and has a significant effect on the kinematic and dynamic performances of the mechanism. In this study, effects of joint clearances on bearing vibrations of mechanism are investigated. An experimental test rig is set up, and a planar slider-crank mechanism having two imperfect joints with radial clearance is used as a model mechanism. Three accelerometers are positioned at different points to measure the bearing vibrations during the mechanism motion. For the different running speeds and clearance sizes, this work provides a neural model to predict and estimate the bearing vibrations of the mechanical systems having imperfect joints. The results show that radial basis function (RBF) neural network has a superior performance for predicting and estimating the vibration characteristics of the mechanical system.     

含间隙机构的动力学仿真与分析

使用ADAMS建立含运动副间隙的曲柄滑块多体动力学模型.根据Hertz理论,设置适当的仿真参数,对含运动副间隙的曲柄滑块模型进行动力学仿真分析.通过理想关节与含间隙关节的接触力以及运动机构中某一点的位移、速度、加速度等结果的比较,得出间隙对机构运动副的影响.     

Effects of restitution coefficient and material characteristics on dynamic response of planar multi-body systems with revolute clearance joint

To study the effects of restitution coefficient and material parameters on the dynamic characteristics of planar multi-body systems with revolute clearance joints, a comprehensive methodology for clearance revolute joints in a planar multibody system is presented and analyzed. A new nonlinear contact force model, which accounts for the axial length of bearing and has a wide suitable range of impact situation, is presented to evaluate the contact force between journal and bearing. Furthermore, a modified Coulomb friction force model also presented to consider the effect of friction in clearance joint. Then, a typical journal-bearing model and a planar slider-crank mechanism has revolute clearance joint are used as examples. From the main numerical results under the different restitution coefficient and material parameters, it can be concluded that coefficient of restitution has significant effects on dynamic response of multi-body systems with revolute clearance joint. Additionally, materials of journal and bearing with smaller Young’s modulus will cause obvious delay on dynamic response of multi-body systems.     

基于间隙运动副的往复压缩机传动机构动力学分析

以往复压缩机传动机构为对象,利用ADAMS软件的碰撞函数,建立带有转动副间隙的往复压缩机传动机构多体动力学模型,研究间隙转动副对机构动力学性能的影响。考虑间隙幅值、气缸载荷、曲轴转速和柔性连杆等影响因素,进行五种工况的动力学分析。仿真的结果表明所述因素对机构的动力学性能影响显著。     

基于静态间隙杆模型的曲柄滑块机构磨损分析

磨损是导致机械设备和机械零部件失效的主要原因之一,磨损与系统动力学响应的耦合对机构的性能均有重要影响。基于一种转动副反力的简化求解模型,进行了一系列的参数研究。结合达朗贝尔原理对曲柄滑块机构进行动力学建模,利用Winkler弹性地基模型获取界面的接触压力分布,使用Archard模型计算间隙副的磨损深度,建立了含间隙曲柄滑块机构的磨损与动力学耦合分析框架;通过与有限元(FEM)方法的比较发现,该磨损计算耦合模型不但具有相当的求解精度,而且在计算效率方面有质的提升。     

多间隙运动副四杆机构运动特性研究

运动副存在间隙会造成机构精确度的降低,为了研究运动副间隙对机构运动可靠性的影响,以含间隙转动副的平行双曲柄四杆机构为研究对象.根据运动副对目标构件的作用特性定义了运动副的性质,利用ADAMS研究了间隙运动副对机构不同目标构件运动特性的影响.结果表明:二级驱动间隙副比一级驱动间隙副对目标杆Ⅲ运动特性的影响更明显,但杆Ⅲ长...