弧面分度凸轮机构参数化设计与仿真

以弧面分度凸轮机构为研究对象,基于VC 面向对象的方法及Pro/E二次开发技术,建立弧面分度凸轮参数化设计系统,该系统给出了界面友好的参数输入对话框,能够完成机构参数的自动综合和凸轮轮廓的自动生成,具有直观性,易于操作和调整,并在Pro/E环境下进行装配、仿真与干涉检测,验证了设计的合理性,为该机构的广泛应用提供了新方法和手段.     

平行分度凸轮机构设计专家系统的开发及三维运动仿真

基于对AtuoCAD与Pro/E的二次开发及综合运用,开发了平行分度凸轮机构的设计专家系统,并实现了运动仿真.该系统给出了界面友好的参数输入对话框,能够完成机构参数的自动综合和凸轮轮廓的自动生成,实现了直接在Pro/E环境下进行仿真.该系统具有直观性、可靠性和易于调整,提高了机构产品的设计质量及效率.     

圆柱凸轮三维参数化设计与数控加工

凸轮机构优良的运动特性和动力特性由精确的轮廓曲面来保证,圆柱凸轮轮廓曲面因从动件运动规律的变化而成不同的复杂空间曲面,给圆柱凸轮精确设计和加工造成了困难。通过对圆柱凸轮轮廓曲面的分析,完成了基于Pro/E系统的圆柱凸轮三维参数化设计,并利用Pro/NC数控加工模块对圆柱凸轮进行了数控加工仿真,自动生成驱动数控机床进行零件数控加工的Numerical Control G代码。     

偏置滚子从动件盘形凸轮机构的参数化设计及运动仿真

针对典型的凸轮机构从动件的推程和回程具有复杂的运动规律,基于对Pro/E的二次开发和综合运用,参照传统图解法的反转法原理,开发了滚子偏置直动从动件凸轮机构的全参数化设计系统,并实现了虚拟装配与运动仿真。该系统根据用户输入的参数,可自动生成16种组合的从动件典型运动规律的凸轮理论轮廓和实际轮廓,提高了凸轮机构产品的设计质量和效率。     

基于Pro/Toolkit的弧面分度凸轮的CAD系统开发

弧面分度凸轮设计繁琐,为此利用Pro/Toolkit在Pro/Engineer平台上开发了一个弧面分度凸轮的设计系统,以辅助设计人员进行设计,简化设计过程。通过对凸轮的参数化设计,并利用计算机自动生成凸轮轮廓曲面数据点的方法,完成了对弧面分度凸轮的设计。     

基于旋转混成的凸轮机构的参数化设计及运动仿真分析

凸轮机构通过高副接触带动从动件可以实现预期运动规律.利用Pro/E的旋转混成功能,对尖顶直动从动件凸轮机构进行了全参数化设计.系统可提供1 6种典型的从动件运动规律组合供用户选择,根据输入的参数,自动生成凸轮轮廓,并应用虚拟装配与运动仿真技术,实现在设计阶段可视地对装配进行干涉检测以及产品设计的合理性分析.     

共轭圆柱凸轮CAD/CAM系统开发与应用

针对共轭圆柱凸轮设计和加工特点,研究了共轭圆柱凸轮的参数化设计和加工程序的自动生成。以Pro/E为开发平台,利用VC++和Pro/Toolkit工具,开发了共轭圆柱凸轮的CAD/CAM系统。应用该系统对某凸缘式共轭圆柱凸轮进行设计。结果表明,该系统可实现多种类型共轭圆柱凸轮的设计与加工,操作方便,实用性强,是共轭圆柱凸轮的快速设计和生产提供了重要手段。     

刀库ATC凸轮的设计与仿真

针对刀库自动换刀装置中的凸轮,通过传统的空间包络共轭原理设计计算弧面凸轮,根据平面四连杆运动特性设计计算了平面槽凸轮,利用VC6.0编写凸轮设计程序,生成两种凸轮的加工数据与凸轮廓面数据,将廓面数据导入Pro/E,对自动换刀机构中凸轮实体进行建模与装配,装配过程中,及时修改了装配错误,重新绘制了零件图,特别是针对凸轮Pro/E建模,能够验证设计凸轮加工数据的正确性,分析了设计过程中出现的弧面凸轮的薄脊问题,运用Pro/E对自动换刀机构的运动仿真,检测了凸轮机构干涉,最终得出符合运动学特性的ATC凸轮。     

盘形凸轮的参数化设计及仿真验证

介绍了利用Pro/ENGINEER进行盘形凸轮参数化设计的两种方法:一种是用可变截面扫描工具并由函数evalgraph调用从动件位移曲线生成盘形凸轮的轮廓;另一种是给定相关方程直接生成盘形凸轮的轮廓曲线.设计者只需输入必要的设计参数,盘形凸轮的三维实体便能再生更新.此外,利用Pro/ENGINEER的机构模块对从动件的运动规律是否符合设计要求进行了仿真验证.     

利用Visual Basic对Pro/E进行二次开发的方法研究

结合Pro/E参数化建模的特点,深入探讨了利用VB对三维建模软件Pro/E进行二次开发的方法;以常用的凸轮机构建模为例,介绍了圆柱凸轮参数化建模的步骤以及利用VB6.0设计独立的程序界面驱动Pro/E 4.0自动进行三维建模的方法。     

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...     

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。     

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。     

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.     

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.     

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。     

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.     

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.