基于J2EE的结构设计规范验算系统

设计规范是结构设计的重要依据，全面掌握规范的设计思想，合理运用规范的设计条文可以帮助工程师准确、高效地完成设计任务。将设计规范与计算机技术相结合，融入到CAD系统，实现“规范程序化”是工程师的愿望。该文基于协同设计的思想，采用面向对象技术设计了基于J2EE平台的结构设计规范验算系统模型，实践证明该系统在一定程度上降低了结构设计数据处理的工作量，提高了设计效率，改善了设计质量。     

An integrated,intelligent design environment

An integrated, intelligent design environment was designed and implemented. The heart of the environment is a userfriendly, menu-driven CAD system integrated with an information controller. The system allows the engineer to design in a feature-based, object-oriented manner. Designs are stored in a data base and checked for manufacturability and assembly by an expert system. This paper describes the design of the information integration controller and the man-machine interfaces of the intelligent design system.     

The complementary roles of expert systems and database management systems in a design for manufacture environment

Effective product design that satisfies functional requirements and can be manufactured easily requires vast amounts of knowledge on the part of the design engineer. This paper focuses on the complementary roles of expert systems and database management systems as they relate to the Intelligent Design System (IDS) in a Design for Manufacture (DFM) environment. Each technology complements the other in its strengths and abilities. The database management system provides during the design process. The expert system provides a reasoning mechanism for identifying manufacturing violations and generating meaningful recommendations. These components work cooperatively with a CAD interface to form a unified, intelligent design environment.An information flow analysis of the Intelligent Design System resulted in the development of three distinct classifications of information within the database: CAD data, a design catalog, and a knowledge base. The CAD data tables employ an, object oriented approach to store specific information about the physical contains cost, weight, and strength characteristics of the standard parts and fasteners used within the system. The knowledge base contains rules and heuristics concerning design and manufacturing methodologies.The placement of the expert system rules in the database represents an innovation. As a result, the expansion and updating of the materials, fasteners, standard parts, or manufacturing processes used by the Intelligent Design System is facilitated without increased due to the efficient management of the knowledge base by the database management system. This allows the designer to modify the knowledge and help the system to learn without the need for a knowledge engineer.     

Interfacing CAD and CAM—A study in hole design

Computer Aided Design (CAD) and Computer Aided Manufacturing (CAM) are modern tools for both the designer and manufacturing engineer. These two tools, however, are not usually integrated into one system. In this study, an effort has been made to connect design and manufacturing by interfacing them into a unified software system. Through this demonstrative CAD/CAM package, the designer interacts with a graphics terminal to enter hole design details; these, in turn, are sent to a generative automatic process planning routing which defines appropriate process plans. In addition, a cost estimate is given which provides the designer with a measure of the economic effectiveness of his design. In the future, it will be possible to interface such systems with part programming routines to obtain explicit machine control information. Such a system represents a significant step toward making totally automated manufacturing a reality.     

USE of computer graphics instruments in application-oriented training

Training in the field of computer graphics usage is important for all engineering courses. Both in design and in production, as well as in technical marketing, graphic representations constitute an important means of expression for the engineer. In connection with the training of engineers, three directions of training can be discerned: basic principles of computer graphics, computer-aided design (CAD) systems with their design and application and employment of CAD systems as a new aid for the designer. Methodical didactic training constitutes a precondition for profitable application of the methods of computer graphics.     

A framework for feature-based representation of the design process

The design process is very complicated and differs with each engineer. The development of computer-based aids for design must take this into consideration and allow for the nuances of the individual. A generic representation of the information used in design is required for the development of any data base that supports the design aid. A properly designed data base or set of data bases can help aid. A properly designed data base or set of data bases can help integrate CAD, expert system, and ancillary programs, thereby forming an intelligent design system. A model has been developed that allows the information requirements of the design process to be analyzed. A data base for an intelligent design system can be developed based on these results.     

一个基于知识的车间辅助设计系统PWADES

ＰＷＡＤＥＳ是一个基于知识的车间辅助设计系统，它集知识库、数据库和图形系统为一体，可以模仿选煤专业工程师完成设备选型、车间布置和绘制工程图。本文讨论它的知识库、数据库、图形系统以及它们的组织结构。     

Intelligent computer-aided-design systems: a synergical approach of artificial intelligénce and engineering

A synergism has begun to surface from the artificial intelligence (AI) and engineering communities: an effort to apply AI techniques to engineering problem-solving activities, and to study problems arisen from various engineering fields as a way to develop AI theories and methodologies. This paper first discusses the needs of such a synergical approach and identifies in a broad perspective some AI techniques currently being applied to engineering. It then describes a system, called KREATOR, which applies qualitative reasoning, a subfield of AI, to computer-aided design (CAD). The key observation is that an engineer designer's qualitative knowledge can offer a good basis for the reasoning of device behaviors. Such knowledge, however, is not captured by conventional CAD systems for lack of good representations. KREATOR is a knowledge capturing scheme that allows the designers to record their qualitative knowledge of how mechanical devices behave, KREATOR then automatically generates qualitative simulations.     

基于组件的典型零部件快速设计系统的开发

文章提出了一种基于组件技术的典型零部件快速设计系统的开发技术,通过开发基于组件的典型零部件设计校核模块,建立基于XML技术的典型零部件的模型库及其管理模块,同时为适应工程图的要求,开发了国标符号程序库,达到了跨多种CAD平台的软件及设计资源复用的需要。并以Pro/E平台为例,通过API接口组件的开发,实现了该平台下的典型零部件的设计计算、造型、生成符合国标的工程图,极大地提高了设计效率。     

Editing 3D models on smart devices

This study proposes a 3D CAD system available on smart devices, which are now a part of everyday life and which are widely applied in various domains, such as education and robot industry. If an engineer has a new idea while traveling or on the move, or in the case of collaboration between more than two engineers, this 3D CAD system allows modeling to be performed in a rapid and simple manner on a smart device. This 3D CAD system uses the common multi-touch gestures associated with smart devices to keep the modeling operations simple and easy for users. However, it is difficult to input the precise geometric information to generate 3D CAD models by such gestures. It is also impractical to provide a full set of modeling operations on a smart device due to hardware limitations. For this reason, the system excludes several complicated modeling operations. This work provides a scheme to regenerate a parametric 3D model on a PC-based CAD system via a macro-parametrics approach by transferring the 3D model created on a smart device in an editable form to a PC-based CAD system. If fine editing is needed, the user can perform additional work on a PC after reconstruction. Through the developed system, it is possible to produce a 3D editable model swiftly and simply in the smart device environment, allowing for reduced design time while also facilitating collaboration. This paper discusses the first-ever system design of a 3D CAD system on a smart device, the selection of the modeling operations, the assignment of gestures to these operations, and use of operation modes. This is followed by an introduction of the implementation methods, and finally a demonstration of case studies using a prototype system with examples.     

A foundation for a knowledge-base computer integrated manufacturing system

The true potential of a CIM system cannot as yet be fully realised. A further requirement is for a device which can extract manufacturing information from the outset. The main aim of the research described in this paper is to develop a knowledge-base system for extracting such information and to promote a coming together of design and manufacture. The major goal must be to enable industry to manufacture without manual intervention. A prototype knowledge-base system called HOLDEX described in this paper is an implementation that relies on combining the advantages of existing technology such as AI, CAD representation schemes, advanced manufacturing systems, man-machine interface and most importantly the encapsulated knowledge of a manufacturing engineer. The aim of the prototype system is to encourage a workpiece designer towards manufacturing standards and to assist him in the use of a general purpose CAD package. One benefit to be obtained from providing such assistance is to facilitate the ease of extracting manufacturing information. The scope of the extracted information includes the detailed specification of a set of cutting tools, the recognition of a list of required activities prior to a machining operation, the recommendation of the appropriate machine tool and the automated design of fixtures.     

Pen–tablet as a CAD interface alternative

Championed by major industry players, pen–tablet computing is an example of the trend towards ubiquitous computing and natural/intuitive human machine interfaces that offers engineers opportunities to change how they interact with and how useful computers can be for performing engineering tasks, in particular, design tasks. Recognising that engineers starting a new design reach first for pen and paper instead of CAD software, a broad survey on the state of the art relating to sketch driven design was done. This paper summarizes and analyses the survey's review of the roles new computer interaction devices can play in the initial stages of mechanical design where few applications exist to support the engineer. The paper starts by briefly reviewing the role of pen and paper in the design process and then discussing the potential of new interaction devices in mechanical CAD modelling, keeping most of the focus on the pen–tablet interface and the human machine interaction paradigms and modes that it makes possible. Context is provided using summaries of some of the survey findings and accompanied by comments regarding some areas worthy of future research. Comparisons between these new interaction paradigms and current windows, icons, menus and pointers-based (WIMP-based) CAD operation are also included.     

A CAD-CAE Integrated Injection Molding Design System

. In the injection molding design process, interaction between design and analysis is very intensive. This is to ensure that the plastic part being designed is manufacturable by the injection molding process. However, such interaction is not supported by current computer-aided systems (CAD and CAE), because design and analysis are realized as isolated modules. Although most of CAE systems provide built-in modeling tools, these are only meant for developing an analysis model with very limited CAD functionality. On the other hand, some CAD systems have allowed certain CAE systems to run under their environments, but inherently they use different data models, thus communication between them is poor. This paper presents an innovative, CAD-CAE integrated, injection molding design system. This system uses an integrated data model for both design and analysis. The system is built on top of existing CAD and CAE systems, which not only greatly saves development effort, but also makes full use of the strong functionality of commercial computer aided systems. The system architecture consists of four layers: a CAD and CAE platform layer; a CAD-CAE feature layer; a model layer; and a GUI layer. Two design cases were studied to illustrate the iterative design-analysis process and use of the developed system.     

Geometric model simplification for distributed CAD

Visualization of CAD models in distributed design environment is an essential feature to support collaborative design. To efficiently transmit and render CAD models geometric simplification can be applied to CAD models. However, it is difficult to use available general geometric simplification algorithms because these algorithms are not designed to handle mechanical CAD parts. Applying general simplification on a CAD model would result in distortion of design features and make them unrecognizable to viewers. In this paper, a novel approach is proposed to exploit trimming information in CAD models to simplify their geometry. Visibility culling is integrated into this approach to facilitate selective refinements. The work introduced here aims to support visualization of multiple CAD models in a distributed CAD environment. Implementation details are included and case studies are demonstrated.     

浅海工程障碍磁特性仿真计算

以设置在浅海拍岸浪区中含有钢轨的筑城性工程障碍为研究对象,从钢轨的材料特性及磁特性的分析入手,应用定量地学的方法,建立起了这一特殊工程障碍的磁场正演计算模型.在仿真计算的基础上,提出了采用磁通门磁梯度探测方案对这一特殊工程障碍实施有效探测的具体方法及其关键技术参数.仿真计算的结果与实际测量的结果基本吻合,据此提出的设计方案在工程研制过程中得到了充分的试验验证.     

3D modelling of the agricultural tractor

The use of a CAD system for the design of tractors is described. The way the system is managed and how it has met its initial objectives are discussed. The problems and benefits of using CAD for tractor design are analysed.     

Intelligent approach to a CAD system for the layout design of a ship engine room

The current layout design of a ship engine room not only depends on a skilled designer but also has many design constraints and regulations to be considered. At preliminary design stage CAD systems need to be intelligent in the sense that they must be able to use knowledge to achieve the designer’s goal. In this paper, we present an approach to implement a practical knowledge-based system for the machinery layout design of a ship engine room. The knowledge-base is implemented and verified in the actual CAD environment of a ship engine room, named MADES (Machinery ArrangementDesign Expert System), which we develop in this study. Design knowledge is represented byobject-oriented concept, and nonmonotonic reasoning enables the values of closely related objects to be consistent. The approaches presented in this paper provide a practical example of a knowledge-based system for complex design problems, and can also provide guidance on implementing an integrateddesign expert system that extends the capability of existing CAD systems.     

A CAD-CAE integration approach using feature-based multi-resolution and multi-abstraction modelling techniques

In spite of the widespread use of CAD systems for design and CAE systems for analysis, the two processes are not well integrated because CAD and CAE models inherently use different types of geometric models and there currently exists no generic, unified model that allows both design and analysis information to be specified and shared. In this paper, a new approach called the CAD/CAE-integrated approach is proposed and implemented by a feature-based non-manifold modelling system. The system creates and manipulates a single master model containing different types of all of the geometric models required for CAD and CAE. Both a solid model (for CAD) and a non-manifold model (for CAE) are immediately extracted from the master model through a selection process. If a design change is required, the master model is modified by the feature modelling capabilities of the system. As a result, the design and analysis models are modified simultaneously and maintained consistently. This system also supports feature-based multi-resolution and multi-abstraction modelling capabilities providing the CAD model at different levels of detail and the CAE model at various levels of abstraction.     

The development and application of CAD/CAM workstations in the GDR

For accomplishing low-attended manufacture, step by step, it is necessary that information handling in technological production planning, management and shop control processes is organized economically. This is especially true with respect to computer-aided product development and production planning, faster order throughput, control of production equipment and delivery of information needed for high equipment utilization with a simultaneous increase in the volume of data processed automatically. These complex requirements call for a new type of approach in information handling technology (CAD/CAM) and corresponding layouts of workstations for the designer and manufacturing engineer. Such CAD/CAM facilities should be user-friendly so that they can be adapted to the user's need and not vice versa.     

DEVELOPMENT OF AN INTELLIGENT PRODUCT DESIGN SYSTEM: INTEGRATION STRATEGIES

Conventional computer-aided design (CAD) packages have drastically reduced the workload of the human designer and shortened the product design cycle. However, the degree of effort and volume of information required to use these tools limit their use to the later stages of design. Intelligent computer-aided design (ICAD) systems have sought to provide a more complete design tool to assist the designer in all phases of design. ICAD systems incorporate conventional CAD elements as well as knowledge engineering constructs. The level of integration between different components of an ICAD system determines its usefulness. Most commercial intelligent CAD packages are tied to a specific set of CAD tools, restricting their application domains. This dependence on specific software tools can be reduced by using general purpose modules to interface with available CAD packages. This paper discusses a method of introducing knowledge engineering technology to help develop an advanced intelligent product design system by integrating ICAD's Concept Modeller with SDRC's l-DEAS package for engineering product design. This integration is necessary because neither the Concept Modeller nor the I-DEAS package provides any unified design environment where users can access both symbolic and numerical design tools as needed to carry out design synthesis and analysis activities. Interfacing engineering design and knowledge processing together is not an easy task. The task is further complicated since it needs to be done only by those who have enough knowledge of both technologies, and also because it may result in reorganization of the traditional design process altogether. The proposed intelligent product design system uses artificial intelligence techniques to take care of human experts knowledge and it advocates the use of several commercial software packages that come from a variety of sources (and are proven to be robust) to perform design synthesis in a cost-efficient and timely manner. The technique described here is relatively easy to implement and is well suited to industrial needs.