MBD技术在坦克装甲车辆研制过程中的应用探讨

针对基于模型的定义(MBD)技术在坦克装甲车辆研制过程中的应用,主要进行基于MBD模型的产品研制数据全生命周期管理、三维数字化模型提取方法、设计数据与工艺数据的技术状态联动等方面研究,探讨了以MBD模型作为设计、工艺、制造的数据载体和依据,在数字化环境下,直接依据三维实体模型开展三维数字化工艺设计,实现设计、工艺、制造协同。     

基于典型工序MBD模型的工艺路线决策研究

为了提高三维数字化制造工艺设计智能化水平,简化工艺路线决策过程,提出一种基于典型工序MBD模型的工艺路线决策方法.在制造特征分类的基础上构建了典型工序MBD模型,该模型融合了工艺决策规则、加工方法、机床和工装等工艺信息.通过加工特征与典型工序MBD模型匹配,减少了工艺决策步骤.为保证工序安排的合理性,定义加工元为最小信息实体,通过加工元的合并、排序,得到最优工艺路线.以飞机双面大框结构件的三维数字化工艺设计实例验证了所提方法的有效性.     

基于MBD的三维装配工艺系统关键技术研究

装配工艺在产品制造生命周期中具有至关重要的地位,作为装备生产制造的最后一道环节,对产品质量影响很大。传统的二维装配工艺卡片虽然具有很好的规范性,但是工艺信息与三维模型分离,生动直观性差,由此带来的数据冗杂与表述不清,直接导致产品装配精度和装配效率的降低。工艺与设计环节完全脱离,导致设计人员设计出的产品无法进行加工生产,亦或是工艺人员在制造环节发现的设计缺陷无法及时反馈到设计环节,以至于浪费大量人力物力。基于MBD的三维装配工艺系统,主要针对基于MBD的数字化定义技术、三维装配指令的生成与管理、三维装配工艺仿真技术、基于XML的装配工艺语义网络等内容进行了深入的研究,构建基于MBD技术的三维装配工艺系统的技术方案和相关技术规范[1]。     

装备制造业三维数字化制造工艺解决方案

三维数字化制造工艺是装备制造业信息化技术发展的新趋势,本文结合我国现阶段制造业状况,全面阐述了以业务驱动的在产品全寿命周期管理环境下的全三维产品设计、工艺设计、仿真分析与验证、数字化制造、在线检测和服务的三维数字化制造工艺解决方案。     

基于MBD的三维装配工艺设计技术研究

基于模型定义(Model Based Definition,MBD)将设计、制造、检验等信息集成于产品三维模型中,成为全生命周期过程中的惟一数据源,基于MBD的三维装配工艺设计技术在航空制造等领域得到了越来越多的应用。本文对基于MBD的三维装配工艺设计技术进行了重点研究,给出了基于MBD的三维装配工艺设计的流程,主要包括三维装配工艺模型构建、装配工艺信息标注、三维装配工艺详细设计及三维装配工艺发放等。     

基矛UG产品工艺信息三维标注应用的探索

MBD 的工艺设计是基于三维设计模型直接完成工艺模型的创建,并在三维工艺模型上完整表达产品工艺定义信息的先进工艺设计手段。在复杂产品制造行业中,MBD 协同设计制造技术的作用越来越大,本文以转向随动臂零件的模型为对象,结合 UG 软件平台,探索了三维标注及三维关联工序模型的具体方法,为企业实现数字化制造打下了基础。     

基于三维数字化模型的加工工时计算方法

为了便于实现零件制造过程中加工工时的定额计算与管理,提出了一种以CATIA软件为平台,面向零件加工工艺过程,基于三维数字化模型的零件加工工时计算方法。该方案在CATIA环境下实现,通过提取三维数字化模型结构树中的零件加工工艺信息,识别并提取三维模型下零件的加工特征,获得相对应的加工工艺数据信息,与已经建立的零件工时给定原则进行匹配计算,从而得到基本作业时间,达到了简化工时计算,快速掌握工时的目的,从而建立一套快速获取零件加工工艺信息和工时计算的软件系统。     

应用基于模型的定义技术建立三维工序模型研究

为了实现零件加工特征中间工序模型的快速生成,提出了一种应用基于模型的定义(MBD)技术建立三维工序模型的方法.分析了设计MBD模型与工艺MBD模型、工序MBD模型间的相互关系,结合数字化工艺设计系统,给出了三维工序模型中孔特征和规则凸台面特征的自动生成技术路线,论述了数字化工艺系统的功能框架及信息模型,并验证了应用MBD技术建立三维工序模型的可行性和有效性.     

带式输送机零部件智能工艺设计系统研发

为改变传统机械零部件设计制造中“三维模型+二维图样”的工艺表述现状,加快企业数字化和智能化技术的推广及应用,在基于MBD工艺模型的建模过程中,分析了MBD工艺模型的内涵及构成,针对三维工艺模型不易生成的问题,提出一种基于MBD的零部件工艺模型三维参数化设计方法。结果表明：通过SolidWorks API和Visual Studio相结合的二次开发方式,利用三维工艺参数化设计方法建立带式输送机零部件的MBD工艺模型,结合特征识别和CBR推理技术,能够实现面向制造的工艺智能设计和产品工艺信息三维表达,从而缩短研发周期,提高设计效率。     

基于模型定义的工艺信息建模及应用

为实现基于模型定义技术在工艺设计中的应用,考虑零件制造的中间状态,以工序MBD模型为基本单位,通过加工特征将几何信息与工艺信息相结合,建立了面向工艺的MBD模型。然后以工序模型为载体,建立MBD的零件工艺信息模型。采用多视图方法,分别将三维标注信息按照专业类型和工艺规划过程进行划分和管理,并将工序模型进一步划分为实体层、扩展层和应用层。以一个工艺信息实例说明了基于模型定义的工艺信息建模在三维工艺规划系统中的应用。     

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.     

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.