利用Solid Edge开发与应用工程图学CAI积件

针对当前工程图学CAI课件开发与使用中存在的内容不可修改、使用灵活性差等诸多不足，提出了利用Solid Edge开发工程图学CAI积件的思想与方法。并已在截交线、相贯线、组合体、机件表达方法、零件图、装配图等课堂内容方面进行了积件开发。积件将现代三维造型方法引入了工程图学课堂教学，立体三维造型与二维投影同时显现、协同变化，充分发挥了计算机与教师的双重作用，使教与学动态结合起来，取得了较好的教学效果。     

由二维视图复原三维立体的新方法

根据工程图学和三维CAD课程的教学实践,研究、总结出一种将三维CAD中立体的构型原理、方法和成型过程用于二维视图阅读的新方法。该方法将传统的二维读图方法与现代三维CAD有关内容融合到一起。按此方法读图,不仅可以使学生根据二维视图快速复原立体空间形状,而且可以了解立体的成型方法和最佳构型过程,为三维CAD构型设计奠定基础。     

运用三维绘图软件SolidWorks改革工程图学教学的实践

指出了二维绘图软件AutoCAD已经不能满足目前企业新产品设计的需要以及现有的多媒体CAI课件仍然不能充分发挥教师的主导作用，不能满足交互性和实时性的教学需求。论述了工程图学引入三维CAD软件的必要性和重要性。运用三维机械软件SolidWorks，提出了三维画法几何，并从三维入手改革了工程图学的教学，连续3年在15个班的学生中进行了试点，取得了良好的教学效果。总结了改革过程中的一些做法和经验。     

三维造型设计与工程图学的有效融合

随着计算机软硬件技术的普及和飞速发展以及制造业对二维计算机绘图以及三维设计造型技术日益增长的需求,在工程图学教学中有效地融入二维计算机绘图以及三维设计造型技术已显得尤为重要。论文介绍了北京理工大学在工程图学和三维造型创新设计方面＂外挂式、分段式和融合式＂三种模式的教学改革实践,并着重对如何将三维造型设计与工程图学有效地融合进行了论述。     

基于ObjectARX开发工程图模块的研究

三维实体建模在机械产品的设计过程中得到了广泛应用,但二维工程图仍是当前指导生产和进行技术交流必不可少的文件。为了从三维实体模型快速得到二维工程图,利用ObjectARX二次开发工具,在AutoCAD平台上开发工程图模块,实现了实体模型向工程图的快速转化以及自动标注。工程图生成在模型空间,方便后续操作。通过实例证明该工程图模块能够从特征实体模型中提取工程图的相关信息,快速生成二维工程图,大大提高用户的工作效率。     

基于特征画法识别的装配图读图方法

针对工程制图课程中装配图读图方法与步骤不易被学生接受,学生自主读图能力差等问题,提出一种新的读图方法“特征识图法”,通过对装配图中传递零件运动信息特征画法的识别,分析其所属零件的动作及相邻零部件的动作,最终看懂装配体的工作原理.该方法以具有特征画法的可运动零件的动作为读图切入点,使平面画法有效地转化为零件动作,激发学生学习兴趣,提高学生在课堂中自主学习的比重.特征识图法是一种有效改变学生“被动学习”角色的自主探索式读图方法.     

利用SolidWorks的组合体读图方法研究

由二维视图表达的组合体读图是工程制图课程中较为重要但又为学生感到抽象的一部分内容,指出了现有的多媒体课件在这个问题上仍然不能发挥教师的主导作用,不能满足交互性和实时性的教学需要。论述了组合体读图中引入三维CAD软件辅助教学的必要性,应用SolidWorks从二维草图到三维实体建模的方法,提出了以匹配线框为形状特征的识图和建模过程,将组合体读图中运用形体分析法的人工思维过程通过三维造型形象地表现出来,从而提高学生的看图能力和空间思维能力。     

基于Pro/Engineer Wildfire的化工设备三维设计技术

结合一个椭圆形封头实例，介绍了在Pro／Engineer Wildfire环境下建立三维化工设备零件库的方法。根据化工设备设计条件单，从所建的零件库中选用筒体、接管、封头、法兰、人手孔等零件，调用所选零件进行整体装配，根据设备的三维设计调整、修改设计方案，定稿后生成二维化工设备装配图作为技术文件备用。从而缩短化工设备的设计周期，提高产品的设计效率和弹性。     

运用SolidWorks和ObjectARX改革工程图学教学方法

随着高等教育的迅速发展,工程图学传统的挂图、模型、板书的教学方式已不能适应教学需求,而多媒体CAI课件又存在着不能展示不同的教学策略,不能随需应变等缺陷。提出用SolidWorks和ObjectARX改革工程图学教学方式的新方法,并论述了这一创新方法的重要性和优越性。说明了用SolidWorks创建三维形体的必要性及其在读图中起到的实物模型无法达到的效果。介绍了用ObjectARX在改进AutoCAD中求第三视图的方法。运用这种灵活多变、实用便捷的教学模式,使得教与学都变得轻松,获得了良好的教学效果。     

采用三维CAD软件的工程图学教学实践

随着三维CAD软件的发展及广泛应用,传统工程图学已发生了深刻的变化,现代工程图学学科已与工程设计有机地联系在一起.在此新形势下,提出在工程图学的教学中,将CAI课件与三维CAD软件相结合,一方面培养学生发散性和创造性思维的能力,另一方面,以设计为主线将各部分教学内容紧密联系在一起,潜移默化中启发学生从设计的角度来分析问题和解决问题.     

基于网络的实时虚拟装配系统的研究

基于网络的虚拟装配为虚拟制造领域提出了一个崭新的思路和方法.提出了虚拟装配过程中约束的实时控制与虚拟装配仿真磁心定位的概念,从产品的装配分析角度出发,实现了网络环境下虚拟装配系统的智能化动态仿真、装配信息实时反馈以及虚拟环境下数据库的快速查询,并研究了仿真动画和交互的关键技术.     

Integrated assembly and disassembly sequence planning using a GA approach

In a product life cycle, an assembly sequence is required to produce a new product at the start, whereas a disassembly sequence is needed at the end. In typical assembly and disassembly sequence planning approaches, the two are performed as two independent tasks. In this way, a good assembly sequence may contradict the cost considerations in the disassembly sequence, and vice versa. In this research, an integrated assembly and disassembly sequence planning model is presented. First, an assembly precedence graph (APG) and a disassembly precedence graph (DPG) are modelled. The two graphs are transformed into an assembly precedence matrix (APM) and a disassembly precedence matrix (DPM). Second, a two-loop genetic algorithm (GA) method is applied to generate and evaluate the solutions. The outer loop of the GA method performs assembly sequence planning. In the inner loop, the reverse order of the assembly sequence solution is used as the initial solution for disassembly sequence planning. A cost objective by integrating the assembly costs and disassembly costs is formulated as the fitness function. The test results show that the developed method using the GA approach is suitable and efficient for the integrated assembly and disassembly sequence planning. Example products are demonstrated and discussed.     

基于UG OPEN的3D-CAAP装配模块的设计与实现

设计了基于UG的三维装配工艺规划与管理系统（3D-CAAP）的构架，着重研究了运用MFC实现CAAP与UG的集成开发，可视化装配工艺规划环境设置、装配顺序、路径规划与编辑、工艺数据的数据库存储与动态连接库调用等关键技术，介绍了实现一种较实用的3D-CAAP系统的解决方案，实现了可视化装配规划、实时纪录装配顺序、装配知识查找、装配顺序、路径编辑修改、装配工艺文件管理的系统整合。     

融合模式下装配图教学过程与绘图方法的改革

联系目标教学改革的实际,多角度全方位地论述了运用ＣＡＩ技术对装配图教学过程进行改革与优化的必要性与具体的做法。深入结合计算机绘图的特点,论述了对装配图教学中的拼图和拆图方法进行的有关改革及创新,提出了一种有利于提高装配图教学效率与质量的新的教学方法和思路。     

维修拆装工艺规划系统的研究

结合装备维修活动中的拆卸与装配问题,明确了研发面向维修的拆装工艺规划系统的必要性.提出了一个拆装工艺规划系统的构架,论述了系统的主要功能模块、工作流程以及所采用的关键技术.实现了装配建模、拆装序列规划、拆装序列评估与优化,以及拆装作业仿真等关键功能.实践表明该原型系统的设计切实可行,具有良好的应用前景.     

应用VRML技术的脉冲爆震发动机虚拟实验系统开发

在脉冲爆震发动机的教学科研中,迫切需要开发一个演示系统结构与运行过程的虚拟实验室系统。以VRML虚拟现实技术为平台和UG三维实体建模为单元,构建了具有交互功能的脉冲爆震发动机虚拟动态实验系统,实现了脉冲爆震发动机的虚拟拆卸与装配以及脉冲爆震发动机系统的虚拟运行。该虚拟实验系统避免了实际试验过程的危险性和涉密性等问题,具备远程教学科研的演示功能。     

Self‐Assembly of Shaped Nanoparticles into Free‐Standing 2D and 3D Superlattices

This article describes a novel supramolecular assembly‐mediated strategy for the organization of Au nanoparticles (NPs) with different shapes (e.g., spheres, rods, and cubes) into large‐area, free‐standing 2D and 3D superlattices. This robust approach involves two major steps: (i) the organization of polymer‐tethered NPs within the assemblies of supramolecular comblike block copolymers (CBCPs), and (ii) the disassembly of the assembled CBCP structures to produce free‐standing NP superlattices. It is demonstrated that the crystal structures and lattice constants of the superlattices can be readily tailored by varying the molecular weight of tethered polymers, the volume fraction of NPs, and the matrix of CBCPs. This template‐free approach may open a new avenue for the assembly of NPs into 2D and 3D structures with a wide range of potential applications.     

Developing assembly line layout for delayed product differentiation using phylogenetic networks

Effective formation of product platforms helps adapt to product demand changes and decrease time-to-market and lead time. The product platform groups the core elements of product family members into a common module used to derive different product variants by combining it with different components. A new delayed product differentiation (DPD) platform network model, which applies median-joining phylogenetic networks (MJPN), is proposed. It is used for forming product platforms and determining the assembly line layout of modular product families. The MJPN is traditionally used for DNA sequences’ mapping, analysis, clustering and tracing evolutionary trends. The concept of assembly/disassembly modular platforms, whereby both assembly and disassembly of components are used to derive the final product variants from the platform, is utilised. The proposed model determines the required number and composition of a product platform and defines the DPD points. The developed dynamic assembly/disassembly platforms enhance routing and product mix flexibility due to having different platforms that can be used to produce the same product variant. A family of household kettles is used to demonstrate the application of the proposed model. A metric is presented for determining the effectiveness of a given platform in delaying the product differentiation, hence increasing the efficiency of mass customisation. The proposed metric, applied to the case study, demonstrated that the proposed platform formation model using MJPN is more capable of postponing the product differentiation point.     

Self‐Correction Strategy for Precise,Massive, and Parallel Macroscopic Supramolecular Assembly

Macroscopic supramolecular assembly (MSA) represents a new advancement in supramolecular chemistry involving building blocks with sizes beyond tens of micrometers associating through noncovalent interactions. MSA is established as a unique method to fabricate supramolecularly assembled materials by shortening the length scale between bulk materials and building blocks. However, improving the precise alignment during assembly to form orderly assembled structures remains a challenge. Although the pretreatment of building blocks can ameliorate order to a certain degree, defects or mismatching still exists, which limits the practical applications of MSA. Therefore, an iterative poststrategy is proposed, where self‐correction based on dynamic assembly/disassembly is applied to achieve precise, massive, and parallel assembly. The self‐correction process consists of two key steps: the identification of poorly ordered structures and the selective correction of these structures. This study develops a diffusion‐kinetics‐dependent disassembly to well identify the poorly aligned structures and correct these structures through iterations of disassembly/reassembly in a programmed fashion. Finally, a massive and parallel assembly of 100 precise dimers over eight iteration cycles is achieved, thus providing a powerful solution to the problem of processing insensitivity to errors in self‐assembly‐related methods.     

A CAD-linked virtual assembly environment

This paper presents a novel approach to integrate VR and CAD for virtual assembly, namely, CAD linked virtual assembly environment. Compared with most existing VR and CAD integration approaches, the proposed approach is a kind of external integration with a CAD system through automation interfaces. A novel hybrid virtual assembly model is developed in this paper to support this external integration. It works as a combinator that links the precisely represented design dataset in CAD models and the corresponding hierarchically structured virtual assembly dataset in the VR application. With this model, a framework has been developed to embed and apply CAD assembly constraints on the virtual assembly structure. Constraint-based manipulation is then implemented in the virtual assembly environment. Moreover, with this framework, advanced computations, such as runtime DOF determination, disassembly directionality computation, and assembly/disassembly sequence generation, which rely on assembly constraint information, can be feasibly integrated into the virtual assembly application with much less effort. The approach is also more practical in terms of implementation due to two advantages: (1) It does not require the implementation of a complicated support for solid modelling in the virtual assembly application. (2) A virtual assembly environment can be automatically created and updated from the linked CAD models.