快开阀用金属波纹管高周寿命设计

通过对煤化工领域用快开阀门的使用工况，分析波纹管疲劳失效形式，针对此类阀门中快速动作的波纹管利用变刚度锥形波纹管设计方法，快速的对原始阀门中的金属波纹管结构方案进行调整，实现大幅增加金属波纹管使用寿命的目的，并通过理论分析和试验验证了变刚度波纹管设计方法对提高快开阀门波纹管使用寿命的有效性。     

金属波纹管密封阀门的结构设计及试验

介绍了金属波纹管密封阀门的结构设计、波纹管类阀门的试验项目和试验方法。     

航天阀门中零泄漏金属波纹管动密封技术及其应用

论述了航天发动机阀门中金属波纹管动密封零泄漏技术的密封原理。介绍了金属波纹管动密封的构成、加工、试验以及在航天阀门中低温、高压、高温工况下的应用。     

波纹管焊接设备的研制

介绍了金属波纹管在阀门中的应用。并叙述了一种简便、高效的波纹管焊接设备的研制过程。提出了简化设计的一些方法。     

阀门用金属波纹管疲劳寿命的有限元分析

应用MSC.Fatigue软件并以应变寿命法分析和得出了阀门用金属波纹管在压力、位移条件下的疲劳寿命。分析了材料的循环性能对波纹管疲劳寿命分析的影响,并且通过波纹管的疲劳寿命试验验证了软件分析的准确程度,从而得到精确的分析结果。     

波纹管阀门的密封结构及其影响因素

文中根据波纹管阀门的使用环境和功能要求,确定了阀门的主要结构材料,设计了阀门的内、外密封结构。在阀门的内密封结构上,采用形如刀口的平面密封,具有平面密封的特点,同时密封轴向力适中;在阀门的外密封结构上,采用与外界无漏点的波纹管密封。同时,内密封性能是波纹管阀门的一个重要技术指标,在研究波纹管阀门内密封的密封机理基础上,分析了波纹管阀门内密封性能的影响因素,如介质的物理性质、密封副质量、表面粗糙度、密封宽度、密封比压等,可为波纹管阀门的设计提供理论依据。     

阀门用金属波纹管的参数和结构设计

介绍了金属波纹管几何参数的设计方法和性能参数的计算方法。讨论了使用寿命估定方法和工作状况对使用寿命的影响。阐述了几种阀门中常用的波纹管端部结构及选用原则。     

降低低温截止阀波纹管破坏率的研究

低温截止阀门是运输液氢、液氧、液氮等低温介质时的关键设备,广泛应用于我国航天领域试车和发射任务中.波纹管是低温截止阀门中重要的组件,起到补偿低温介质引起的阀门管壁伸缩变形的作用.在低温阀门的制造、组装和试验的过程中,阀门波纹管的破坏率较高,使得阀门局部或整体结构失效,难以修复.论文通过对实际操作的调研和理论研究,从人员、设计、工艺、材料等方面分析了导致阀门波纹管破坏的原因,并基于这些破坏的原因制定了一系列避免波纹管损坏的方法,有效避免了在阀门的制造、组装和试验过程中波纹管的破坏,达到了降低阀门的生产成本、缩短阀门的生产周期,保证阀门的高可靠性的目的.     

阀门用金属波纹管摇摆试验及在线监测技术的研究

介绍了阀门用金属波纹管在工况系统中的使用功能、安装尺寸及试验要求。分析了波纹管摇摆疲劳试验设备、辅助的联动机构及在线监测系统试验验证的技术特性。给出了产品试验技术的研究和实施过程,为后期产品设计提供了有效的数据。     

CONVAL软件及控制阀在苛刻工况的应用（下）

七 关于直行程控制阀的外漏 随着对环保的要求越来越高，如何提高直行程控制阀阀杆密封、防止阀杆外漏的问题已经普遍被各个阀门制造商所关注。对于这类控制阀的阀杆密封，通常采用波纹管密封和普通填料密封两种技术，波纹管从材质上主要有金属波纹管和PTFE波纹管。     

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。     

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....     

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.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.