Development of a Special Machine Rotating Cutter Based on Virtual Prototyping

We first describe the fundamental concept of virtual prototyping(VP)technology and discuss the differences among VP,computer aided design,computer aided engineering and computer aided manufacture.Then we present the application flow of virtual prototyping technology to the development of mechanical products.Based on ADAMS/VIEW,a new kind of special machine rotating cutter has been developed.The simulation results show that the rotating cutter meets the design requirements.Is is concluded that virtual prototyping technology is quite valuable in designing and manufacturing mechanical product.     

Destructive disassembly to support virtual prototyping

The design paradigm called virtual prototyping (VP) is important because of the need to manufacture products in a short period of time and in a cost effective manner. By replacing the building of physical prototypes for testing various design issues such as usability, life-cycle analysis, functionality and so on with so called “virtual models” on a computer and analyzing them, virtual prototyping is achieved. One of the design issues that has become increasingly important is the “design-for-disassembly (DFD)” paradigm. A well designed product that is easy to disassemble has the obvious advantages when it needs to be taken apart for service or end-of-life recycling. Therefore a design tool that can tie the DFD issues into a virtual prototyping system is of considerable interest. This paper attempts to address this particular issue in the virtual prototyping area: DFD as applied to VP. This paper presents an overview of a detailed DFD method. An algorithm that can be readily tied into a computer aided design system, therefore also useful for virtual prototyping, is discussed. Some implementation issues and an evaluation of the effectiveness of the DFD method currently employed are explained. Even though this research is still in its early stages, the paper presents a general framework of DFD methodology and its potential to be used as a virtual prototyping tool.     

Rapid prototyping and flow simulation applications in design of agricultural irrigation equipment: Case study for a sample in-line drip emitter

In this study, a 3D CAD solid model of a sample agricultural irrigation emitter was created and the flow behaviour was simulated in its labyrinth channels by using a flow simulation technique. Referenced by the original design, the channel geometry was modified and the emitter was re-fabricated using rapid prototyping/additive manufacturing techniques. The flow behaviour is then re-investigated based on the re-shaped channel geometry of the labyrinth structure. The predetermined optimum pressure in the pipe was validated experimentally for both the original design and modified designs. As a result, the optimum pressure in the pipe and the flow characteristics for original both the design and modified designs of the emitter were validated. This study contributes to further research into the development of agricultural irrigation equipment aided through the utilisation of additive manufacturing and computer aided engineering tools.     

Manufacturing data analytics using a virtual factory representation

Large manufacturers have been using simulation to support decision-making for design and production. However, with the advancement of technologies and the emergence of big data, simulation can be utilised to perform and support data analytics for associated performance gains. This requires not only significant model development expertise, but also huge data collection and analysis efforts. This paper presents an approach within the frameworks of Design Science Research Methodology and prototyping to address the challenge of increasing the use of modelling, simulation and data analytics in manufacturing via reduction of the development effort. The use of manufacturing simulation models is presented as data analytics applications themselves and for supporting other data analytics applications by serving as data generators and as a tool for validation. The virtual factory concept is presented as the vehicle for manufacturing modelling and simulation. Virtual factory goes beyond traditional simulation models of factories to include multi-resolution modelling capabilities and thus allowing analysis at varying levels of detail. A path is proposed for implementation of the virtual factory concept that builds on developments in technologies and standards. A virtual machine prototype is provided as a demonstration of the use of a virtual representation for manufacturing data analytics.     

小型回旋加速器虚拟样机技术

小型回旋加速器虚拟样机技术是把小型回旋加速器的理论计算、分析、信息技术与机械设计、加工、装配、调试、运行、维修等专家知识进行有机结合，在系统仿真和虚拟现实基础上发展起来的一种新概念技术。基于虚拟样机，可以实现创新设计，有效降低探索风险。文章探讨了回旋加速器虚拟样机系统框架，讨论了虚拟样机系统的体系结构和回旋加速器产品的全生命周期仿真，提出了基于全生命周期集成和多学科协同设计的回旋加速器虚拟样机的开发思路。     

Virtual prototyping and manufacturing planning by using tri-dexel models and haptic force feedback

This paper presents a new method of using the tri-dexel volumetric models and a haptics force feedback for virtual prototyping and manufacturing planning. In the proposed method, the initial polyhedral surface model is converted to a tri-dexel volumetric model by using a depth-peeling dexelization algorithm. In the virtual prototyping process, the tri-dexel volumetric model is updated by the swept volume of a moving cutter via a haptic force feedback interface device. A collision detection algorithm is proposed for the virtual sculpting and the pencil-cut planning with real-time haptic force feedback to the users. Tool paths are generated for machining the virtual sculpted parts via the simulation and verification on a virtual CNC machine tool before they are actually machined. Computer implementation and practical examples are also presented in this paper. The proposed method enables the haptic-aided virtual prototyping and manufacturing planning of complex surface parts.     

Virtual prototyping and manufacturing planning by using tri-dexel models and haptic force feedback

This paper presents a new method of using the tri-dexel volumetric models and a haptics force feedback for virtual prototyping and manufacturing planning. In the proposed method, the initial polyhedral surface model is converted to a tri-dexel volumetric model by using a depth-peeling dexelization algorithm. In the virtual prototyping process, the tri-dexel volumetric model is updated by the swept volume of a moving cutter via a haptic force feedback interface device. A collision detection algorithm is proposed for the virtual sculpting and the pencil-cut planning with real-time haptic force feedback to the users. Tool paths are generated for machining the virtual sculpted parts via the simulation and verification on a virtual CNC machine tool before they are actually machined. Computer implementation and practical examples are also presented in this paper. The proposed method enables the haptic-aided virtual prototyping and manufacturing planning of complex surface parts.     

A framework of virtual prototyping environment for the design and analysis of mechanical mechanism with clearance

Mechanical mechanisms with clearance abound in technological fields such as robotics, machine and steam turbine industry. The dynamic performance of these mechanisms in working condition can be achieved provided that the effects of the different on the mechanisms (such as mechanism dynamics, technological effects and thermal behaviour) are thoroughly understood. Virtual prototyping provides an integration of multi-domain dynamic simulation for the design and analysis process. In the current paper, a framework of virtual prototyping environment for the design and analysis of mechanical mechanism with clearance is presented. A case study with such a simulation strategy is studied for the optimum design and analysis of the technological parameter.     

The measurement of heat distribution in stereolithography electrodes during electro-discharge machining

Early work by the authors explored the potential for manufacture of electrodischarge machining (EDM) electrodes, using rapid prototyping (RP) technologies. A number of possible routes were identified to provide an integrated system from computer aided design (CAD) data through to production tooling. One such route is the processing of stereolithography (SL) RP models by electrodepositing copper onto the metallized surface. This strategy provides a process route from model to tool with minimum manual intervention. Initial studies using thin-coated SL models for EDM have identified a limitation to application due to heat build up in the electrode. Currently, the electrodes can be used at low material removal rates (MRR), commonly known as semi-roughing or finishing cuts. Higher MRR generates greater heat at the cutting face which causes failure of the RP electrodes. This failure is believed to occur through a combination of delamination, thinning and distortion of the electrode. The heat distribution and associated failure modes for these electrodes are being investigated to determine how the machining performance can be improved.     

A framework of virtual prototyping environment for the design and analysis of mechanical mechanism with clearance

Mechanical mechanisms with clearance abound in technological fields such as robotics, machine and steam turbine industry. The dynamic performance of these mechanisms in working condition can be achieved provided that the effects of the different on the mechanisms (such as mechanism dynamics, technological effects and thermal behaviour) are thoroughly understood. Virtual prototyping provides an integration of multi-domain dynamic simulation for the design and analysis process. In the current paper, a framework of virtual prototyping environment for the design and analysis of mechanical mechanism with clearance is presented. A case study with such a simulation strategy is studied for the optimum design and analysis of the technological parameter.     

A simulation environment for dry-expansion evaporators with application to the design of autotuning control algorithms for electronic expansion valves

In this paper some results of a research project aimed at deriving high-performance, adaptive control algorithms for electronic expansion valves (EEVs) to be used in finned-coiled, dry-expansion evaporators for refrigeration systems are reported. With the aim of developing a software environment that can be used for controller design, rapid prototyping, optimization of data collection and test design, virtual prototyping approach to design was adopted. The development of a distributed dynamic simulation model of the evaporator coupled with an electronic expansion valve, and its use for deriving autotuning PID control algorithms is described. Experimental results confirm the effectiveness of this kind of approach.     

基于虚拟仿真技术的灌装生产线设计与仿真

目的 针对灌装生产线的设计与验证过程,基于虚拟仿真技术,实现灌装生产线的快速设计与验证。方法 首先通过分析灌装生产线的生产过程,利用SolidWorks三维建模软件分别对灌装生产线中的灌装机、搓盖机、贴标机、喷码机、装箱机等设备设计三维模型。然后将所有设备的三维模型导入Demo 3D仿真软件,进一步按照各设备的动作流程对模型进行动作设计及运动规划,构建灌装生产线虚拟仿真系统。最后根据设备功能和生产产能要求,在虚拟仿真系统中通过不断地调整设备机械结构及机构的运行速度,最终实现灌装生产线的快速设计与迭代优化。结果 得出灌装生产线的优化设计方案,并根据该设计方案研制出灌装自动生产线,生产线的产能为2400 瓶/h,满足企业要求。结论 该方法能够实现灌装生产线的快速设计与验证,缩短设计开发周期,减少设计和验证成本。     

Virtual reality prototyping of bio-molecules

Modelling, sharing and transmission of three-dimensional (3D) graphics data of biomolecules are essential in many bio visualization tasks from collaborative research and education to molecular simulation and drug discovery. In the current paper, modelling and representing of bio-molecular structure for virtual and physical rapid prototyping is presented. Our aim is to devise a uniform solution for visualizing, browsing, interacting and prototyping of bio-molecules in various environments including internet, immersive virtual reality (VR), and rapid manufacturing. To do so, we use non uniform rational B-spline surfaces (NURBS) to represent protein secondary structure and surface structure. NURBS protein structures are then tessellated to form bio-molecular graphics models. Their triangular mesh representation is next extracted from their scene graph. A geometric optimization process is followed to make data compatible for their formatting in compact and consistent VR standard to support protein internet browsing, protein VR visualization, protein 3D rapid prototyping and crystal sub-surface laser engraving.     

Virtual reality prototyping of bio-molecules

Modelling, sharing and transmission of three-dimensional (3D) graphics data of biomolecules are essential in many bio visualization tasks from collaborative research and education to molecular simulation and drug discovery. In the current paper, modelling and representing of bio-molecular structure for virtual and physical rapid prototyping is presented. Our aim is to devise a uniform solution for visualizing, browsing, interacting and prototyping of bio-molecules in various environments including internet, immersive virtual reality (VR), and rapid manufacturing. To do so, we use non uniform rational B-spline surfaces (NURBS) to represent protein secondary structure and surface structure. NURBS protein structures are then tessellated to form bio-molecular graphics models. Their triangular mesh representation is next extracted from their scene graph. A geometric optimization process is followed to make data compatible for their formatting in compact and consistent VR standard to support protein internet browsing, protein VR visualization, protein 3D rapid prototyping and crystal sub-surface laser engraving.     

基于虚拟样机技术月球机器人运动仿真

采用“虚拟样机”技术,建立一个集三维实体设计,动力学建模,控制,可视化仿真于一体的虚拟月面计算机仿真环境,对月球机器人的静力学,运动学以及动力学进行仿真研究,为月球机器人结构参数,动力学参数及控制算法的优化提供了设计参数和验证场所。     

基于虚拟高冲击样机的装备寿命预测研究

讨论了虚拟样机(virtual prototyping)的意义和必要性，简要介绍了ADAMS仿真系统。以承受高冲击激励的火炮为研究对象，分析了影响火炮工作性能的主要因素，总结了火炮正常工作的三个基本准则。运用Fortran语言编制了火炮故障仿真模块，在ADAMS环境下建立了火炮高冲击虚拟样机。结合层次分析法(AHP)确定了性能的影响权重，制定了基于虚拟高冲击样机的火炮工作性能评估方案，进而对火炮剩余寿命进行预测，仿真结果证明了评估和预测研究的有效性。最后，展望了虚拟样机的应用前景和下一步的研究重点。     

Motion generation and virtual simulation in a digital environment

The growing complexity in product design and manufacturing processes has made virtual prototyping an important new approach that enhances products and process development. Considering the ergonomic issues evident in product lifecycles, digital human modelling (DHM) is adopted for virtual simulation and proactive evaluation. A motion generation from semantics (MGS) system is proposed in this research. The MGS system features include virtual prototyping, natural language instruction, a method time measurement (MTM) translator and motion generator. The system was implemented using product lifecycle management (PLM) software and validated in an automotive manufacturing company. The practice of intuitively generating manual operations and conducting virtual simulations enables the system planners to quickly respond to manufacturing process changes and recursively improve the tooling and process design flexibility and efficiency.     

Pairwise Meta-Modeling of Multivariate Output Computer Models Using Nonseparable Covariance Function

Gaussian process (GP) is a popular method for emulating deterministic computer simulation models. Its natural extension to computer models with multivariate outputs employs a multivariate Gaussian process (MGP) framework. Nevertheless, with significant increase in the number of design points and the number of model parameters, building an MGP model is a very challenging task. Under a general MGP model framework with nonseparable covariance functions, we propose an efficient meta-modeling approach featuring a pairwise model building scheme. The proposed method has excellent scalability even for a large number of output levels. Some properties of the proposed method have been investigated and its performance has been demonstrated through several numerical examples. Supplementary materials for this article are available online.     

CAD／CAE及其在机械产品研发中的应用

计算机的发展和广泛应用给机械科学带来了革命性的变化，以虚拟样机为代表的CAD／CAE是其在设计中的具体体现，本文从机械产品研制的角度出发，阐述了CAD与CAE的关系，虚拟样机技术的内涵，总结了有限元法和虚拟样机技术在机械产品设计研究中的应用情况，并指出了目前国际上虚拟样机的研究重点。     

筒式柴油打桩机工作场景的计算机拟实制作

采用计算机辅助设计和辅助造型软件3DS MAX对筒式柴油打桩机动态工作场景进行了拟实制作,加深了人们对其工作原理、结构特点以及装配关系的认识,提升了筒式柴油打桩机的研究水平。所采用的技术和方法既能促进机械设计技术的创新发展,也能促进计算机拟实设计技术的创新应用,还可为其他领域的设计工作提供帮助。