基于.NET4平台读写AutoCAD文件

鉴于AutoCAD在各个行业中的广泛应用,目前的技术只是停留在把AutoCAD图档元素信息以文件的形式保存起来,然而随着项目团队对AutoCAD文档的交叉设计,实现如何让不同的设计数据共享起来,是个非常重要的问题。本文针对AutoCAD图档中的各种元素(如文本框、矩形框等)信息进行读取,并将其保存到其它形式的数据存储介质(如XML或MS SQL Server、Oracle等关系型数据库)中,方便对AutoCAD图档文件进行更智能化的信息化管理。AutoCAD文件本身也是一种数据库,文件扩展名为DWG,只是该数据生态链没有和日常中经常使用的XML或MS SQL Server、Oracle等关系型数据库存储介质进行交互传递。其实根据XML或MS SQL Server、Oracle保存的数据,我们反过来可以修改AutoCAD文件中文本框、矩形框的相关信息参数,这样我们就可以和AutoCAD文件进行数据交互了,读和写DWG文件中的元素信息。     

基于.NET4平台读写AutoCAD文件

鉴于AutoCAD在各个行业中的广泛应用,目前的技术只是停留在把AutoCAD图档元素信息以文件的形式保存起来,然而随着项目团队对AutoCAD文档的交叉设计,实现如何让不同的设计数据共享起来,是个非常重要的问题。本文针对AutoCAD图档中的各种元素（如文本框、矩形框等）信息进行读取,并将其保存到其它形式的数据存储介质（如XML或MS SQL Server、Oracle等关系型数据库）中,方便对AutoCAD图档文件进行更智能化的信息化管理。AutoCAD文件本身也是一种数据库,文件扩展名为DWG,只是该数据生态链没有和日常中经常使用的XML或MS SQL Server、Oracle等关系型数据库存储介质进行交互传递。其实根据XML或MS SQL Server、Oracle保存的数据,我们反过来可以修改Auto-CAD文件中文本框、矩形框的相关信息参数,这样我们就可以和AutoCAD文件进行数据交互了,读和写DWG文件中的元素信息。     

用Delphi3.0实现SQL/Server和FoxPro之间的数据转换

Microsoft的SQL/Server是一种大型数据库系统,许多应用软件都以它为数据库平台。但在SQL/Server中查找数据,必须在网络环境,如果把SQL/Server表转换成FoxPro的表(DBF文件)就可以方便灵活的在单机中查看,这为查找数据和报表提供了方便。本文阐述如何用Delphi3.0实现两者之间的转换。     

SQL Server6.0性能优良 客户众多

微软公司最近宣布,它的客户机/服务器数据库管理系统Microsoft SQL Server 6.0版正式发货。这个在微软Windows NT Server网络操作系统上新的分布式数据库平台,使微软公司为所有组织存取和管理重要商业信息更容易、更便宜而提供可缩放数据库技术。 做为服务器软件家族Microsoft BackOffice的一个重要组成部分,SQL Server 6.0是可缩放的、高性能的DBMS,专为分布式客户机/服务器计算环境而设计。它的强有力的分布式管理工具、内置的数据复制和开放系统体系为实现投资效益好的信息解决方案提供了跨越多种硬件的理想平台。     

二次开发Pro/TOOLKIT下的Pro/ENGINEER外部数据库访问及模型的尺寸驱动

在对Pro/ENGINEER进行二次开发的过程中,经常需要对Pro/ENGINEER外部的数据库进行访问,或从外部数据库获得参数以实现模型的尺寸驱动.对外部数据库的访问,按其访问方式通常可分为单机访问和客户/服务器访问两种,其数据也被储存在诸如Access或SQL Server等不同的数据库中.     

基于SQL Server 2005的数据挖掘技术在石油储运中的应用

介绍了SQL Server 2005数据挖掘平台及其功能,较详细地给出了SQL Server 2005数据挖掘过程,论述了基于SQL Server 2005的数据挖掘技术在石油储运信息中的实现.通过对石油储运的数据资源挖掘的研究,希望能为石油储运中存在问题的解决给予一定的帮助.     

用C#.NET实现对SQL Server数据库的备份与还原

介绍了在C#.NET环境中,实现对SQL Server数据库的备份与还原,它能在数据服务器崩溃或Microsoft SQL Server系统崩溃时有效、快速地恢复数据,保证了Microsoft SQL Server中数据的完整、安全。     

OPENDATASOURCE函数的海量数据快速导入导出

主要阐述在OLEDB和Delphi环境下,基于Transact-SQL中OPENDATASOURCE函数的SQL Server数据库海量数据快速导入导出方法,给出了SQL Server数据库与SQL Server、Oracle、Access和Excel等OLE DB支持的外部数据库之间实现数据导入导出的具体程序代码。     

基于ObjectARX和ADO.NET的列车线路图计算机辅助设计

针对列车线路图设计出图的实际需求,设计了使用ObjeetARX.NET和ADO.NET的技术方案,并针对列车线路图进行元素建模、分析设计和编程实现.该技术方案同时使用了AutoCAD计算机辅助设计软件、SQL Server2005数据库、Visual Studio 2005程序设计平台的ADO.NET数据访问技术和C#程序语言等多项主流技术.     

基于Java的建筑能耗监控系统

通过MyEclipse10.0和SQL Server 2008开发了一个建筑能耗监控平台,系统采用Java语言的JDBC数据库访问技术,SQL Server 2008数据库语言以及Java语言中的图形化库等,实时更新显示能耗数据,并对数据进行分析和管理,有效地实现了监控的目的。     

基于Patran和MSC Nastran的压电智能桁架结构振动模态分析

用Patran和MSC Nastran分析压电智能桁架结构振动模态,验证基于有限元法建立的智能桁架结构机电耦合动力学模型的正确性和有效性.结果表明：采用Patran和MSC Nastran针对2种典型压电智能桁架结构开展振动模态分析的结果,与采用基于有限元法建立的数学模型计算得到的模态频率及实验测试模态频率近似相等,验证基于有限元法模型的正确性和有效性,为开展主动振动控制器的设计提供模型和技术支持.     

Fuzzy finite element analysis of imprecisely defined structures with fuzzy nodal force

This paper presents the fuzzy finite element analysis for static displacements of fixed free stepped rectangular beam, truss and simplified bridge structure with fuzzy nodal force. The material and geometric properties of the structures are taken as crisp. Fuzzy finite element analysis of static problem for the above structures converts the problem into fuzzy system of linear equations. As such the coefficient matrix and the right-hand side vector become crisp and fuzzy respectively. A new approach is used here to solve the fuzzy system of linear equations. Numerical results for the three stepped rectangular beam, three-bar truss and simplified bridge with fifteen elements are presented to illustrate the computational aspects of the developed method. The results obtained are depicted in term of plots.     

三维渗流有限元软件GWSS开发与应用

针对复杂地质条件的三维地质建模、复杂建筑物的几何建模和复杂防渗排水系统作用下渗流场精细模拟等三维渗流场有限元分析的难点问题,采用IDL开发面向水工结构和岩土工程的渗流有限元分析软件GWSS（Ground Water Simulation System）.该软件包括系统控制模块、数据管理模块、前处理模块、计算模块、后处理模块和制图输出模块等六大模块.前处理模块具有基于钻孔和钻孔剖面的三维地质建模、几何建模与有限元网格生成等功能;计算模块主要用于各种闸坝、堤防、隧道和地下洞室等渗流问题的计算分析等;后处理模块可显示各渗流要素的三维云图和任意截面的二维云图等.GWSS已经在国内四十多个工程的渗流计算中得到应用和检验.     

Dynamic analysis of wind-excited truss tower with friction dampers

This paper presents a rational analytical method for determining dynamic response of wind-excited large truss towers installed with friction dampers and investigates the effectiveness of friction dampers. The analytical procedure involves two models of one truss tower: one is the two-dimensional lumped mass dynamic model and the other is the three-dimensional (3D) finite element static model. These two models are alternately used to fulfill control force transformation, displacement increment transformation, and the numerical integration of equations of motion of the coupled damper-tower system. A three-story truss structure under wind excitation is used to validate the proposed bi-model method through the comparison with a precise 3D dynamic analysis. After a satisfactory comparison, a large space steel television tower is used as an application to examine the feasibility of the bi-model method and the effectiveness of friction dampers. The case study shows that the bi-model method can efficiently compute wind-induced response of the large space television tower with friction dampers and the installation of the friction dampers of proper parameters can significantly reduce wind-induced vibration of the tower.     

考虑间隙运动副的桁架单胞等效建模与分析

本文主要研究了含间隙运动副桁架单胞的等效建模方法.主要考虑了桁架单胞的等效刚度问题以及阻尼问题.首先从间隙铰链开始研究,提出全面的铰链模型;其次提出用位移法将桁架单胞等效成板,即把桁架单胞看成是由梁元组成的钢架结构,运用平面钢架位移法得出桁架单胞的等效刚度矩阵,进而得出结构的整体固有频率和等效后的板的刚度矩阵.最后用有限元软件ANSYS对单胞结构在不同边界条件下进行了模态分析,将在自由边界条件下的固有频率和解析得出的频率做了对比,发现二者有很好的吻合度.结果表明由于间隙运动副的存在,使得桁架单胞结构的刚度降低,柔性增强.     

Geometrically nonlinear finite element reliability analysis of structural systems. II: applications

This is the second part of an investigation on finite element reliability analysis of geometrically nonlinear elastic structures (GNS). This study concentrates on applications. The linkage code RELSYS-FEAP presented in the companion paper is used for finding both component and system reliabilities of GNS. Structural reliabilities are evaluated for both geometrically linear and nonlinear elastic behaviors. Two geometrically nonlinear applications are presented, including a truss and a suspended structure. The stress and displacement reliabilities of the truss are computed considering both geometrically linear and nonlinear elastic behaviors. The system reliability of a geometrically nonlinear suspended structure is evaluated. The structure is modeled as a series of parallel subsystems according to three system failure criteria. The effects of correlation between loads, correlation between resistances, and material behavior (brittle or ductile) are evaluated and discussed. Finally, displacement reliability indices of the suspended structure are computed.     

An emulator for minimizing computer resources for finite element analysis

When many calculations are involved in the finite element analysis, emulating the solution steps provides a basis to efficiently establish an optimum computer implementation strategy. The SCOPE emulator described herein determines the computer resources required as a function of the structural model, load and deflection conditions, type of analysis, storage allocation plan, and computer hardware capability. It provides data for trading the analysis implementation options to arrive at a strategy that consumes a minimum of computer resources. The models contained in the code lead to micro-operation counts for each finite element analysis step, as well as to estimates of the total computer analysis resources. Application of SCOPE to the analysis of an existing truss/frame structure provides measures of the accuracy of resource assessments. Data indicates that predictions for ELAS finite element code on the AMDAHL 470 V/8 computer are within 17.3% for (CPU) calculation time, and within 3.2% for peripheral (I/O) storage resources.     

桁架自适应结构振动控制仿真实验研究

基于MATLAB／dSPACE综合仿真实验环境,在有限元结构分析的基础上,在MATLAB／Simulink中进行桁架自适应结构的数学模型搭建和控制方案设计仿真,由dSPACE软硬件系统实现自适应结构的主动元件驱动和传感器数据采集,从而实现半物理仿真。实验表明基于MATLAB／dSPACE综合实验环境桁架振动受到很好的抑制,证明MATLAB／dSPACE试验环境高效简洁,控制方法行之有效。     

Finite element analysis of maneuvering spacecraft truss structures

A finite element modeling and solution technique capable of determining the time response of flexible spacecraft truss structures undergoing large angle slew maneuvers has been developed. The elastic deformations of the structure are coupled with large nonsteady translational and rotational motions with respect to an inertial reference frame. The governing equations of motion of the system are derived using momentum conservation principles and the principle of virtual work. The finite element approximation is applied to the equations of motion and the resulting set of nonlinear second order matrix differential equations is solved timewise by an iterative direct numerical integration scheme based on the trapezoidal rule. The solution technique is tested on both planar and three-dimensional maneuvering spacecraft truss structures.     

基于ANSYS二次开发的结构拓扑优化

将先进的结构拓扑优化思想与成熟的有限元分析软件ANSYS相结合,基于ANSYS二次开发语言APDL和UIDL编制了结构拓扑优化程序,解决了ANSYS自带的拓扑优化模块中单元类型受限及不能应用于桁架结构优化的问题,充分利用ANSYS丰富的单元类型、强大的计算和后处理能力,有利于促进结构拓扑优化的应用和研究,拓宽ANSYS软件在结构拓扑优化方面的应用领域。