卷弧翼火箭弹的参数化建模方法

针对多学科设计优化的需求,综述了几种常用的参数化建模方法.对卷弧翼火箭弹参数化建模的基本原理和实现步骤进行了详细说明.利用UGNX提供的API开发了参数化建模的内部和外部程序,可为空气动力学科计算提供几何模型和为弹道学科计算提供弹体标志量信息.     

玻璃容器计算机辅助设计系统的IDEFO和IDEF1x模型

从系统建模的角度,以啤酒瓶计算机辅助设计系统为例,采用IDEF方法建立CAD系统的功能模型和信息模型,为高效地建立玻璃容器计算机辅助设计系统提供了实现方法.     

基于时序逻辑的工作流建模与分析方法

提出了一种基于活动时序逻辑(TLA)的工作流建模与模型分析的形式化方法.该方法将模型及模型的性质都表示为一个TLA公式,对工作流模型性质的分析可以等价为对TLA中两个公式之间是否存在蕴涵关系的检验,从而建立了一个工作流模型各层次分析统一框架.一个工作流建模和分析的实例验证了所提出方法的有效性,该方法在建模、模型分析以及指导模型设计等方面都有较好的应用前景.     

面向企业能效评估的能源消耗过程建模方法研究

针对企业能效评估对能源消耗系统模型的需求,在分析企业能耗过程的组成因素及其相互作用关系的基础上,提出了一种将企业的生产过程、物料移动、资源配置、余能回收利用等数字化的,基于模糊高级Petri网的企业能源消耗过程建模方法,并详细地给出了模型的形式化定义、运行规则以及建模原则.实例分析表明,该方法独立于特定的能源类型和用能设备,实现了能耗过程结构和动态行为方面信息的全面描述,是企业能源消耗过程分析与优化的基础.     

基于流程的面向对象企业建模体系结构研究

重点讨论了针对企业信息集成的模型体系结构的相关问题。首先讨论了针对企业信息集成建模的限制因素，以及由此产生建立企业动态模型体系结构的要求。其次讨论了面向对象方法在企业建模领域应用的问题。最后，在对若干流行的体系结构(特别是ARIS)分析的基础上，建立了基于流程的面向对象企业模型体系结构，给出了该体系的模型框架、各主要视图、视图间关系和建模的实施步骤。     

虚拟筛分实验系统的层级建模技术研究

以往的研究解决了在OpenGL环境下进行复杂模型的转换和生成问题,但对于由多个具有配合关系部件组成的模型,直接转换后将丢失各部件间的关系等信息,从而影响模型在虚拟仿真系统中的应用.为建立实用的虚拟筛分实验系统,提出了一种基于OpenGL的层级建模方法,用树形结构描述模型各部件间的层级关系,采用嵌套显示列表技术实现模型绘制.应用表明该建模方法简单有效,能够用于构建具有复杂模型的虚拟场景.     

基于MBD的飞机钣金件参数化建模技术

分析了基于模型定义的技术内涵与数据集内容,以及它的信息表达规范.为提高设计效率,在用CAA对CATIA二次开发时,采用参数化方法建立规范的基于模型定义(MBD)的零件模型.针对飞机钣金件的结构,分别阐述了MBD零件模型几何信息和非几何信息表达的参数化技术.两侧翻边钣金肋的MBD模型实例证明,该建模方法提高设计效率20%以上,可以显著缩短产品的开发周期.     

基于SysML模型的需求建模及测试方法

为了将模型驱动测试有效应用于嵌入式系统测试中,本文说明了需求建模方法以及用例生成方法,以及SysML建模语言中状态机图的抽象语法、图元符号和形式化语义,针对性能测试要求,总结了关于状态机模型的性能测试建模方法,并通过实例构建状态机图描述性能需求,建立测试场景分析方法,有效覆盖系统的性能测试类型.经验证,采用基于模型驱动...     

面向工程应用的生物信息系统化建模研究

生物信息在工程中的应用是仿生方法研究的核心.已有方法缺少对生物知识在工程中系统转化的支持,难以分析复杂的生物信息,造成了仿生设计的效率低下.为解决这一问题,分析了现有理论中对生物信息的分析策略,结合生物耦合机制等新理论,以工程系统的建模为基础,提出了一套面向工程应用的符号化生物信息模型,能够有效地对生物原型中的功能特性和系统特性进行描述和分析,同时是面向工程设计人员的,与传统的产品功能特性和系统组成的建模策略具有很好的相容性,克服了传统方法部分局限性.最后通过生物信息建模实例,验证了本方法的实用性与可行性.     

基于ObjectARX实现特征建模的方法

为了满足中小企业实施CAD/CAM集成过程中对产品特征模型的需要,基于特征设计的建模理论,建立了特征的信息模型。研究了在AutoCAD系统上实现特征建模的方法,阐述了特征的参数输入、定位、生成及存储等特征建模的主要步骤。以齿轮泵泵体特征建模为例,证明了基于ObjectARX实现特征建模的可行性,为中小企业实施CAD/CAM集成提供了一种简单而有效的方法。     

An Intelligent Logistics Management Model in Prefabricated Construction

In recent years, with the increasingly complex fabricated construction environment and increasingly challenging logistics management requirements, this paper proposes a model of intelligent logistics management based on radio frequency identification and building information modeling, which enables monitoring full life cycle of building components and improving construction efficiency through real-time uploading and tracking components and materials logistics information. The empirical model was typically used in the construction of a major theme park with good results achieved.     

基于坐标变换的功能梯度材料空间映射建模研究

随着3D打印零件复杂性和多样性的日益增加,单一材质的零件已无法满足各类特殊性能要求,功能梯度材料零件逐渐成为快速成型制造行业的研究热点。为满足功能梯度材料的制造要求,提出了一种基于坐标变换的功能梯度材料空间映射建模方法,该方法的关键是将几何信息与材料信息有效结合。首先,采用单梯度源法、多梯度源法构建功能梯度材料模型的材料空间,在遇到交叉梯度源模型时利用特定的相交算子以一定的权重比进行材料分布计算。然后,在几何空间与材料空间结合的过程中,巧妙地通过坐标变换将材料空间与几何空间的坐标系重合,实现将材料空间映射至几何空间,从而得到带有材料信息的功能梯度材料模型。通过修改梯度源、材料分布函数以及坐标变换方法即可获得所需的功能梯度材料模型。利用Visual Studio 2019软件和OpenGL编程语言对实例模型进行可视化分析的结果表明,所提出的建模方法相比于大部分估值建模、非估值建模方法可大大缩短建模时间,从根本上解决了某些算法所造成的储存空间不足和建模过程繁琐等问题。基于坐标变换的功能梯度材料空间映射建模方法为增材制造行业提供了一种新的建模方法,具有良好的应用价值。     

Development of a BIM-based production planning and control system for Lean Construction through advancement and integration of existing management techniques

As part of general construction management, production planning and control is vital for successful project delivery. Numerous approaches supporting production planning and control exist in practice and research. However, the different approaches focus on distinct areas such as workflow stabilization or cost control, and no single system combines all the requirements of a holistic production management system. Varying production management systems can be explained by the unique characteristics of many construction projects. As an approach for the digital twinning in the construction industry, building information modeling (BIM) can help standardize production management through shifting the management system design toward the digital prototype. Previous scientific work has acknowledged this approach, thereby generating numerous concepts for using building information models within construction management approaches. However, BIM is often merely used as a parallel support rather than as an integral part of production management systems. To address this gap and in terms of research methodology, we follow a Design Science Research approach. Thus, we propose a new BIM-based production management system, which is characterized by a theoretical integration model for BIM and existing construction management techniques, and a methodology for applying these concepts in practice.     

Framework based on building information modeling,mixed reality,and a cloud platform to support information flow in facility management

The quality of information flow management has a remarkable effect on the entire life cycle of buildings. Manual retrieval of technical specifications and features of building components and their performance assessment leads to increased cost and time and efficiency reduction, especially during the facility management (FM) stage. The introduction of building information modeling (BIM) in the construction industry can provide a valuable means of improving the organization and exchange of information. BIM tools integrate multiple levels of information within a single digital model of a building. Nevertheless, the support given by BIM to FM is far from being fully effective. Technicians can benefit from real-time communication with the data repository whenever the need for gathering contextual information and/or updating any data in the digital model arises. The framework proposed in this study aims to develop a system that supports on-site operations. Information requirements have been determined from the analyses of procedures that are usually implemented in the building life cycle. These studies set the standard for the development of a digital model of a building, which will be shared among various actors in charge of FM and accessed via a cloud platform. Moreover, mixed reality is proposed to support specific information that is relevant to geometric features and procedures to be followed by operators. This article presents three use-cases supported by the proposed framework. In addition, this research article describes the first proof of concept regarding real-time support for FM.     

工程机械出口行业客户关系管理数据仓库建模研究

以工程机械行业的客户关系管理系统建设为背景,围绕客户价值分析主题构建数据仓库维度模型．对客户关系管理数据仓库维度建模过程中的需求分析、高级维度模型设计、详细维度模型开发、维度模型评审和确认4个阶段进行了相应的规定描述,形成可供ETL、数据挖掘、联机在线分析等使用的数据仓库维度模型构建方案．     

箱体零件CAD／CAPP／CAM集成系统的研究与实践

在ＣＩＭＳ环境下，针对箱体零件ＣＡＤ、ＣＡＰＰ、ＣＡＭ信息集成的功能需求，在基于特征的箱体零件信息模型、工艺计划模型与服务于工艺设计的制造环境模型的支持下，开发出了特征造型，工艺设计及加工过程仿真与ＮＣ编程等子系统，从而完成了一个集成化的箱体零件ＣＡＤ／ＣＡＰＰ／ＣＡＭ系统。     

基于IFC标准和工程信息模型的建筑施工4D管理系统

在工程建设项目的实施过程中,需要处理大量复杂的工程数据信息。如何合理有效地组织和利用这些信息,最大程度地实现工程项目各参与方和不同专业应用系统之间的信息交流和共享,是当前我国建设领域信息化亟待解决的问题。通过对建筑业国际工业标准IFC和4D模型理论的深入研究,建立基于IFC和工程数据管理的4D信息模型,支持建设项目实施的各个阶段的数据交换与共享,实现工程信息的集成化管理,开发面向建筑施工的4D项目管理系统,实现了建筑施工进度、资源、场地布置的动态管理、优化控制和4D可视化模拟。为工程建设项目全过程的工程信息管理和利用提供理论、途径和方法,为建筑施工管理提供新的辅助工具。     

Revisiting digital twins: Origins,fundamentals, and practices

The digital twins (DT) has quickly become a hot topic since it was proposed. It appears in all kinds of commercial propaganda and is widely quoted by academic circles. However, the term DT has misstatements and is misused in business and academics. This study revisits DT and defines it to be a more advanced system/product/service modeling and simulation environment that combines most modern information communication technologies (ICTs) and engineering mechanism digitization and characterized by system/product/service life cycle management, physically geometric visualization, real-time sensing and measurement of system operating conditions, predictability of system performance/safety/lifespan, and complete engineering mechanisms-based simulations. The idea of DT originates from modeling and simulation practices of engineering informatization, including virtual manufacturing (VM), model predictive control, and building information modeling (BIM). On the basis of the two-element VM model, we propose a three-element model to represent DT. DT does not have its unique technical characteristics. The existing practices of DT are extensions of the engineering informatization embracing modern ICTs. These insights clarify the origin of DT and its technical essentials.     

基于三维查找表的CRT色空间转换的研究

彩色显示器是用来传达颜色信息的重要工具,而色彩在不同设备和系统上往往会造成差异,因此对显示器建立一个色彩管理系统很有必要.采用三维查找表的方法建立了RGB-CIELab色彩空间转换模型,完成了模型的色差计算与精度分析,取得了较好的实验结果,为建立显示器的色彩管理系统提供了依据.     

A hybrid crystal plasticity and phase transformation model for high carbon steel

Presence of retained austenite in two-phase steels can have a significant effect on the response of the material. The current state-of-the-art in multi-phase modeling of polycrystalline plasticity has limits on scaling, explicit phase modeling, and tracking multiple plasticity types. To address these issues, a hybrid material model is developed for high-carbon steels. The model can account for crystal plasticity of martensite and stress-assisted transformation from austenite to martensite in dual-phase high-carbon steel. The parameters of the model are calibrated to experimental stress-strain and volumetric transformation strain data. The combination of scalability and multiple phase representation gives a useful tool for the investigation of two-phase high-carbon steel behavior.