齿轮传动系统的动力学与模态分析

为了提高齿轮设计的准确性,结合UG软件参数化建模功能,建立齿轮传动三维实体模型。利用ADAMS软件对齿轮传动系统进行了动力学分析,在高速传动中施加实际传动载荷,得到了齿轮传动系统的振动频率范围和高频率点。通过ANSYS Workbench软件对齿轮传动系统和单一齿轮模型进行模态分析,得到齿轮传动系统和齿轮模型的固有频率和振型,通过与动力学分析得到的频率进行对比,验证了齿轮传动系统的设计准确性,从而为今后齿轮的传动分析提供了数据支持,并为传动过程中的故障分析提供了参考。     

仿生球形凹坑表面形态对旱地洋葱插秧机高速齿轮动力学特性的影响分析

分插机构中高速齿轮的传动性能直接影响着旱地洋葱插秧机的插秧精度与使用寿命。以工程仿生学和有限元理论为基础,为实现齿轮的参数化建模,在SolidWorks软件中建立了高精度齿轮模型,运用ANSYS Workbench软件分析了仿生球形凹坑表面形态齿轮的动力学性能。通过对普通齿轮和仿生球形凹坑表面形态齿轮(仿生齿轮)进行模态分析及静力学分析,分别计算出前10阶固有频率及振型,同时分析了其接触应力与应变状态,并用nCode软件对仿生齿轮和普通齿轮进行了疲劳寿命分析。结果表明,相对于普通齿轮,仿生齿轮的各阶最大振幅更小,其固有频率数值和范围明显减小,整体趋势更加平稳。仿生齿轮可改善接触应力分布状态,减小接触应力,还能存储磨屑并形成局部油池,从而降低齿轮的磨损程度。仿生齿轮的最大疲劳损伤和最小疲劳寿命相对于普通齿轮分别减小了27.64%和增大了38.16%,有效改善了齿轮的力学性能,提高了齿轮传动的可靠性和使用寿命。     

基于ARAMIS系统的微线段齿轮承载接触能力研究

目前微线段齿轮还没有统一的静强度公式进行齿轮的接触承载能力计算,也没进行具体的齿轮接触承载能力研究分析。采用ARAMIS非接触应变测量系统测量微线段齿轮在静加载的情况下齿轮的接触应力,并在相同的试验条件下,分别对微线段齿轮和渐开线齿轮在齿轮啮合处附近及齿根处进行应变分析,得到齿轮端面的主应变图,在两种齿形齿轮相同的位置处选取点进行受力分析,并根据公式计算应力大小,比较这两种齿形齿轮的受力情况。     

基于ANSYS分析的齿轮设计

采用ANSYS有限元方法对减速器渐开线斜齿圆柱齿轮进行分析计算。利用三维软件Solid Works建立齿轮的实体模型,并将简化后的模型导入ANSYS中,选用Solid 45作为齿轮的单元,得到齿轮的有限元模型。然后对齿轮进行模态分析,分别对大齿轮和啮合齿轮进行仿真分析,计算出了齿根弯曲应力和齿面接触应力。有限元分析结果表明,齿轮满足设计要求。     

减速器输出人字齿轮温度场分析

随着齿轮传动向高速、重载方向发展,齿轮温度场分析变得越来越重要.齿轮温度场分布不均会直接影响齿轮传动装置的承载能力和稳定运行状态,甚至会直接导致齿轮失效.通过建立大型船用人字齿轮减速器装置齿轮稳态温度场的数学模型,对减速器齿轮本体温度场进行有限元分析.并对计算结果进行综合评价.     

永磁齿轮的理论研究和有限元分析

在现代化生产中,永磁齿轮传动是一种新型传动方式.通过将永磁齿轮和传统齿轮的对比,得到了永磁齿轮传动的优点,并总结说明了永磁齿轮与传统齿轮的差别.通过对永磁齿轮传动原理的研究,分析了传动性能的影响因素.建立了永磁齿轮的物理模型和数学模型,引入了永磁齿轮传动的数值计算方法.最后采用有限元分析对永磁齿轮传动进行了模拟和计算,...     

基于ANSYS的双圆弧齿轮静动力学分析

基于Pro／E平台,通过参数化方法建立了某双圆弧齿轮的三维几何模型,并利用有限元分析软件ANSYS对其进行了网格划分。对双圆弧齿轮进行静力学分析,获得了该双圆弧齿轮的弯曲应力应变图,由模态分析得到齿轮的各阶振型图,由瞬态分析得到齿轮某一节点的位移图。这些分析结果真实地反映了齿轮的受力及变形情况,有利于齿轮传动技术的完善与提高。     

铝锭堆垛机传动系统齿轮的有限元模态分析

研究了铝锭堆垛机翻转装置传动系统中齿轮的固有振动特性,运用有限元分析软件ANSYS对齿轮进行了模态分析,计算出了固有振动频率和模态振型,为齿轮传动系统的动态响应计算和分析奠定了基础。通过有限元法分析了传动系统各个齿轮的固有振动特性,用有限元分析软件ANSYS计算出了齿轮的各级模态频率和振型,为传动系统的齿轮动态设计提供了参考,也为诊断齿轮传动系统故障提供了一种方法。     

圆弧齿轮有限元分析专用软件网格的自动划分

在自主开发的圆弧齿轮有限元分析专用软件中,利用三维有限元法对圆弧齿轮进行力学计算,关键技术是圆弧齿轮有限元模型的网格划分。针对OpenGL绘制的四圆弧齿轮三维实体模型,提出了一种用于分析四圆弧齿轮的网格自动划分方法,包括四圆弧齿轮端面网格自动划分、三维实体网格的自动划分。输入齿轮基本参数即可实现四圆弧齿轮有限元模型的网格自动划分。此方法符合四圆弧齿轮的几何结构特点,并能满足有限元分析的精度要求。     

胶印机滚筒齿轮接触有限元分析

通过Pro／E软件建立对开胶印机橡皮滚筒和压印滚筒齿轮模型,导入到ANSYS中进行分析,得出齿轮啮合存在干涉和应力集中现象,需要对齿轮进行修形。然后又分析了摩擦力对齿轮接触应力的影响,设置10个不同摩擦系数,对同一模型进行齿轮的接触有限元分析,通过分析结果得出摩擦力对齿轮接触的影响,结果表明齿轮的接触应力随着摩擦系数的增大有增大的趋势,当啮合齿轮没有摩擦力时,轮齿的最大接触应力最小。研究结果显示,摩擦对齿轮接触的影响不可忽视。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.