三维几何模型的中性文件格式数据交换方法研究

现在CAX系统多是以单元自动化为目标来开发和应用的,各系统的数据在逻辑结构和物理结构上均存在较大差异,产品数据交换就成为一亟待解决的问题.在今后较长时期内多种数据交换标准并存的事实条件下,提出利用三维几何模型的中性文件格式之间的数据交换来解决该问题.简介了中性文件交换的接口方案及交换过程,详细讨论了中性文件格式的数据交换方法并给出了应用中性文件格式的数据交换方法实现三维几何模型的转换实例.     

三维几何模型的中性文件格式的数据交换方法研究

现在CAX系统多是以单元自动化为目标来开发和应用的,各系统的数据在逻辑结构和物理结构上均存在较大差异,产品数据交换就成为一亟待解决的问题。在今后较长时期内多种数据交换标准并存的事实条件下,提出利用三维几何模型的中性文件格式之间的数据交换来解决该问题。简介了中性文件交换的接口方案及交换过程,详细讨论了中性文件格式的数据交换并给出了应用中性文件模式的数据交换方法实现三维几何模型的转换实例。     

基于零件库标准的产品信息建模技术

基于STEP标准对产品全生命周期信息进行规范化描述，是产品信息交换的基础，但高层次语义描述能力较弱。零件标准（PLIB，ISO13584）从设计方法学角度出发，研究零件定义与产品无关时，零件库信息在计算机中的合理表达与交换，实现企业资源共享。PLIB通过总模型类，功能模型类和功能视图模型类及其结构，来表示产品开发设计方法和产品多域多级别视图。本文重点给出了产品几何视图信息建模，为产品其他视图的建立提供了一种方法。     

浅析CAx系统间数据交换标准及其应用

本文就机械制造行业进行集成制造系统建设过程中面临的产品数据交换与共享的问题，提出了建立图形描述的通用标准的解决办法。阐述了数据交换的基本原理，并详细介绍了两种应用最广泛的标准-IGES和STEP。给出了利用这些标准进行CAx系统间交换的实例。指出了图形交换标准发展的方向。     

面向并行设计的产品特征信息建模方法

提出一种基于产品特征模型与STEP数据交换标准的并行设计框架,给出一种支持并行设计的产品信息模型体系结构,并成功应用于汽车后桥主传动器系统的开发实践中。     

基于ROSE类库实现数据交换的方法研究

STEP物理文件交换是不同系统之间进行数据交换最基本的途径，也是实现STEP标准的最基本的方式，本文主要研究STEP文件的生成方法。文中的研究分为两部分，即文件头段生成方法和数据段生成方法，其中数据段部分又用2种方法实现，分别是早联编和迟联编方式。最后给出具体实例详细说明生成方法。     

产品数据客户定制系统的数据交换技术研究

分析了产品数据客户定制系统对数据交换的基本要求,对产品数据客户定制系统实现所需关键技术进行了探讨和研究,提出了基于XML的产品数据共享与交换的实现方法,使系统能够根据用户的需要,利用XML文档和STEP文档之间的转换,实现产品数据的共享。     

产品数据集成复杂性与STEP-NC实现方法的研究

阐述了产品模型数据交换标准集成架构，以及应用参考模型、应用解释模型分别所起的作用，说明产品模型数据交换标准集成的价值和映射的复杂性；比较了两个标准，得出AP238具有集成优势，而ISO14649容易实现。以产品模型数据交换标准特征为例，说明了产品模型数据交换标准实现的复杂性，然后给出一种编译映射表的新实现方法，从而综合两个标准的优势。     

齿轮设计Web CAD系统中STEP标准的应用

介绍齿轮设计的Web CAD系统的总体结构:描述系统主要模块的功能及设计原理,重点阐述产品模型数据交换标准(STEP)在系统图形数据交换模块中的功能实现形式.     

不同CAD系统中产品数据交换方法

以STEP和宏-参量法为例介绍了产品数据交换过程以及存在的问题。分析了在不同CAD系统之间进行产品数据交换的方法。     

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...     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

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.     

Fifth International Summer School on Screw-Theory Based Methods in Robotics

正3-11 September,2014University of Bologna,Bologna,Italy www.summerscrews.org summerscrews2014.ing.unibo.it SUMMER 20SCREWS 14In 2014,our screw-theory school comes to the world's oldest university.In early September,Summer Screws'14 will gather six experts in the application of screw theory in robotics and up to 40 participants at the University of Bologna,Bologna,Italy.The school will teach attendees how to apply existing methods and empower them to develop new ones in their own research.The basic theoretical notions will be introduced in a rigorous manner,emphasizing examples,applications,and exercises.Scholarships are available.     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

INDUSTRIAL ENGINEERING AND VISUALISATION-A PRODUCT DEVELOPMENT PERSPECTIVE

Taking the actual project of teaching and researching process for example, the relationship between the industrial engineering and product development is discussed. And use the novel visualization technology to support the industrial engineering and product development. How to use the new computer modeling and simulating technologies to support the product development and industrial engineering, is introduced especially. The support includes both domestic products and industrial systems. The visualization and computer technologies take a very important role in some system or multi-direction modeling, those technologies mentioned above can help the industrial engineers study the effect of design on the whole life circle, including the producing steps. So the engineers can avoid making the wrong decision which may cause bad effects on the whole industrial engineering.