基于KBE与ActiveX的机械产品异步式参数化设计研究

针对目前参数化设计存在的不足,提出了进程外异步模式参数化设计思想,利用面向对象技术开发了基于知识工程(KBE)的机械产品参数化设计平台(PDS-MP).PDS-MP结合CBR方法综合表达产品设计实例,并以三维CAD系统API模块为接口,采用ActiveX Automation技术及消息通信,实现.NET开发的PDS-MP与CAD系统的无缝集成.借助表格、产生式规则及特征三种驱动方法进行设计,在知识重用和产品信息共享的基础上快速实现三维建模与虚拟装配,为数字化设计与制造提供了高效、准确、实用的方法.     

利用KBE与ActiveX的机械产品异步式参数化设计研究

针对目前参数化设计存在的不足,提出进程外驱动(外异步模式)参数化设计思想,利用面向对象技术开发了基于知识工程(KBE)的机械产品参数化设计平台(PDS-MP)。PDS-MP结合基于实例的推理(Case Based Research,CBR)方法综合表达产品设计实例,并以三维CAD系统API模块为接口,采用ActiveX Automation技术及消息通信,实现.NET开发的PDS-MP与CAD系统的无缝集成。借助表格、产生式规则及特征三种驱动方法进行设计,在知识重用和产品信息共享的基础上快速实现三维建模与虚拟装配,为数字化设计与制造提供高效、准确和实用的方法。     

内燃机整机参数化设计与研究

与零件的参数化设计技术相比,整机产品的参数化设计技术可以提高产品设计效率,简化设计操作.通过深入研究内燃机结构特征,获得了该类产品结构设计知识及装配设计步骤.以此为基础,应用Pro/ENGINEER及其二次开发工具Pro/ToolKit,开发了一个内燃机整机产品三维参数化CAD系统的原型,并介绍了系统开发中的关键技术.     

钢坯吊具集成设计系统的研究与开发

基于计算机辅助技术(Computer-Aided Design,CAD)和计算机辅助工程(Computer-Aided Engineering,CAE)集成技术,为实现机械产品的设计流程化、自动化,将三维参数化CAD/CAE系统及输出功能集成到统一界面,形成了开放式的结构设计和分析系统.以钢坯吊具为例,介绍了钢坯吊具集成设计系统的框架组成、设计方案及流程,为大型机械结构的集成设计系统提供开发思路,有利于产品的标准化、系列化及提高产品的科学化管理.     

考虑结构非线性特征的参数化形状优化方法

提出并实现一种将参数化设计技术应用于考虑结构非线性特征的形状优化设计领域的新方法。参数化设计技术是近年来发展起来的新一代CAD软件平台的核心技术之一。文中基于三维参数化CAD平台，将参数化设计技术、有限元建模技术与有限元分析优化系统集成为参数化的形状优化系统；引入非线性分析技术，以解决工程上大量存在的非线性形状优化问题。该方法克服了以往形状优化方法应用于三维实体结构时所面临的几何形状描述、约束与驱动的困难，为机械产品三维结构优化设计提供一个新途径。     

基于Pro/E的离心风机参数化程序设计

这里介绍利用Pro／TOOLKIT编程技术进行参数建模的基础上，通过Pro／E与MFC的接口，对离心风机三维模型进行参数化设计，实现了离心风机的参数化CAD系统。提高了产品的设计效率，对其它的三维参数化CAD系统也很有借鉴定作用。     

机床结构三维参数化形状优化设计

基于计算机辅助设计(Computer aided design, CAD)和计算机辅助工程(Computer aided engineering, CAE)集成技术,开发三维参数化结构形状优化设计平台POSHAPE,为复杂三维机械零部件的设计提供一种通用的工具.为实现优化设计流程的自动化,将三维参数化CAD系统、有限元分析、优化求解和有限元建模等模块集成为完整的通用三维实体参数化形状优化设计系统,形成开放式的结构分析与优化设计集成系统.以CD6140A车床的导轨部分为例,在三维参数化特征造型CAD系统中,以三维实体结构几何模型为对象,以几何尺寸参数为优化设计变量,采用POSHAPE对结构进行形状优化设计,在降低车床质量的同时提高结构刚度和结构自振频率.优化设计结果为机床设计提供重要理论依据.     

产品逆向设计中特征和约束的重建

利用目前逆向工程软件重建的实物CAD数字化模型,只能实现对产品几何形状的复制,因此设计者不能对CAD模型进行更进一步的编辑修改及再设计。提出了通过将逆向设计软件与三维参数化CAD系统相结合的方法,由实物的点云模型反求出CAD模型,此方法反求出的不仅仅是实物的几何形状,而且可用参数化的方法重建出各特征、特征间的几何约束和设计者的设计意图,从而使反求出的模型支持对复制产品的再设计。     

产品建模中的知识管理技术研究

分析了当前参数化技术特点及不足,提出了面向产品建模的知识管理技术,并对设计知识的表达、知识求解与一致性维护等提出了有效的解决方案,在此基础上,开发了一个面向产品建模的知识管理引擎,并应用于国产三维CAD系统中。     

基于Solid Edge的三维模型通用参数化程序设计方法

阐述了基于三维CAD系统的三维模型参数化设计方法 ,提出了用设计变量作为三维模型样板与参数化设计程序相联系的纽带 ,从而大大提高了程序设计效率和程序的通用性。以SolidEdge三维软件为例 ,采用VB开发技术 ,实现了三维模型的通用参数化程序设计     

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...     

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。     

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...     

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。     

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.     

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.     

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.