全自动系列给水设备

BYG 系列给水设备由几台给水泵构成的主系统、气压水罐副系统和电控系统组成。它采取补气罐和喷射泵为空气压缩机构,并且不受储水箱水位高低的限制,对气压水罐实施所需要的快速或慢速补气。该设备采用水控限流阀,可最大限度地实现气压水罐小型化;采用水控补气阀,可在任何时刻     

基于Nastran的防护板动力学分析

针对摩托车二次补气管防护板底盘试验振动断裂问题,建立了基于有限元软件MSC Nastran的动力学模型,并对防护板进行了动力学分析,对比了频率响应和瞬态响应及其直接法和模态法的差异。仿真结果表明频率响应和瞬态响应分析的结果一致。且通过模态实验和应力测试的方法对计算结果进行了验证,为振动疲劳断裂问题提供了解决的思路。     

摩托车防护板有限元分析及其优化研究

针对摩托车二次补气管防护板底盘试验断裂问题,进行了模态分析,找出了产生共振的模态频率和振型。通过对防护板进行动力学响应分析,计算出了结构薄弱位置以及应力分布,并对防护板结构进行形貌优化,得到满足加工工艺的加肋方案,以提高模态频率避开共振。且通过模态试验和应变测试的方法,验证了优化结构的合理性,从而为振动疲劳断裂问题提供可行的解决思路。     

运用知识工程的摩托车设计系统研究

综合运用知识工程(KBE)技术、动态设计技术等,在摩托车总体设计阶段预测系统的动态特性,研究整车的动态性能匹配.构建了基于KBE的摩托车总体设计系统结构,研究了其工作流程和各应用子系统的功能结构,开发了基于KBE的摩托车总体设计系统--MCODS,通过实例验证了系统的可行性和实用性.     

人-机-路环境下摩托车刚柔耦合系统动力学研究

目前摩托车系统动态特性研究一般采用多刚体动力学方法,没有考虑摩托车车架空间柔性体、人和路对摩托车动态特性的影响,致使其动态特性与实际存在较大的差别.把车架作为空间柔性体,考虑发动机和路面激励,建立了人-机-路环境下摩托车系统刚柔耦合动力学模型,对其加速、制动、转向等工况下系统的动态特性进行了仿真和评价,试验验证了理论分析的正确性:对摩托车通过国家B级路面和凸台两种工况下系统的平顺特性进行了仿真和道路试验,研究结论对摩托车整车开发及动态性能优化有一定指导意义.     

工质替代对压缩机环状阀的主要影响因素研究

对制冷压缩机的气阀采用不同工质时的运动规律进行了研究。研究结果表明 ,气体密度的差异是导致气阀运动规律变化的主要因素。同样工况下 ,高密度气体需要匹配较大的弹簧力。更换工质后 ,可以通过调整气阀的刚度、升程以及弹簧的预压缩量来改善气阀的运动规律     

往复压缩机吸气阀通道内流场数值模拟研究

往复压缩机的效率首先取决于气阀,气体的非稳态流动是引起阀片的非正常运动(颤振、关闭延时)原因,也是气体流动损失的主要原因。利用标准k-ε模型对吸气阀口形状及进出口通流面积之比进行了流场数值模拟,结果表明,随着吸气阀口的倾斜角度增大,气阀通道出口两侧的涡旋区域越大,造成流体的压力损失也就越大,另外还研究发现吸气阀的进出口通流面积之比值越小,流体的压力损失越小。最后通过试验验证了仿真的正确性。     

LJ265MQ摩托车发动机的研制开发

主要介绍了LJ265MQ摩托车发动机的研制过程,及该产品在开发中如何结合柳州机械厂现有的LJ276M及LJ465Q汽油机的生产设备技术,充分发挥厂内存量资产的作用,保证工艺继承性及零部件的通用性,并对化油器进行台架匹配试验和整车匹配试验,对发动机动力性进行了标定。     

摩托车车架结构动力优化设计

应用MSC.Nastran对某型摩托车车架结构的动态特性进行研究,将其计算结果与试验模态分析结果做比较,验证车架有限元模型的准确性.然后从引起摩托车振动的两个根源(路面激励和发动机激励)出发,着重从发动机激励方面考虑,通过对车架结构进行动力优化设计,有效地避免了摩托车常用工况下车架前几阶固有频率与发动机的一、二阶惯性力频率一致引起的摩托车共振问题,从而改善摩托车的动态特性,提高摩托车的乘坐舒适性和耐久性.     

往复式压缩机中片状阀频率、模的形状及动态应变的精确测定

引 言 在压缩机中经常损坏的一个部件是气阀,而气阀的损坏绝大多数是由金属的疲劳造成的。采用某种方法预测气阀在运行条件下的寿命是很重要的。预测气阀寿命的一种方法是用计算机模拟气阀动态以求得气阀的应力水平,再将应力水平和疲劳寿命联系起来。     

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.     

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....     

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.     

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.