冷却运输机滚子输送链的接触分析研究

通过具体分析和实例计算验证计入链和链轮的加速度变化所引起的附加动载荷效应的关于链传动受力的计算公式所具有的必要性和良好的实用性;并且基于I—DEAS9．0软件分析了链条和链轮啮合时链轮和滚子的接触强度及销轴和套筒的接触强度。     

基于RecurDyn和MATLAB的链传动仿真系统

本文从实际应用的链轮传动装置入手,介绍了使用RecurDyn软件进行链传动系统分析的流程,与MATLAB软件的交互以及仿真结果,给出了基于MATLAB和RecurDyn软件的链传动仿真分析系统。     

砌块劈裂机链轮推杆结构的设计分析

论述了链轮推杆机构在砌块劈裂机中的重要作用，对链轮推杆机构的组成及其工作方式作了重点论述；对其主要零部件链轮的设计做了详细计算；对动力轴进行了选型和有限元分析，对其总变形和等效应力进行了校核。     

CAD在蜗形凸轮设计中的应用

1．引言蜗形凸轮机构是机械设备中运用很广泛的间隙运动机构之一，其参数选择灵活、传动平稳。分度精度高。蜗形凸轮的设计是该机构设计中的重要工作之一，目前普遍采用人工设计方法，其步骤为：选择从动件运动规律，计算机构的运动参数和几何尺寸参数，进行动力学计算，最后绘制零件图。这一系列繁杂的设计过程给设计者带来许多困难，工作量大，设计周期长。同时由于大量繁杂、重复的设计计算，使人工设计难免出错。而运用CAD技术进行蜗形凸轮设计，可使设计和工程计算、分析及模拟结合起来，实现优化设计，同时正确、迅速地绘制工程图。…     

16A三排滚子链轮三维实体造型设计

根据实际工况需要及标准链轮设计计算手册,设计非标准力矩式16A三排滚子链轮二维CAD图,如图1。为生成三维实体,为链轮零件CAM做准备,实现该零件的无纸化制造,现采用当今CAM领域应用较为广泛的CAXA造型方法。该方法可输出多种格式数据,可被常用CAM软件接收,从而控制数控设备,进行精确、高效的自动加工。     

盒形件拉深模CAD系统研究

本文介绍了自行开发的盒形件拉深模 Ｃ Ａ Ｄ 系统的功能、结构及实现方法。系统运行时，只要输入零件尺寸数据就可根据菜单选项和人机对话完成整个设计过程，最后输出工序图、模具零件图和装配图。     

EBZ160掘进机行走部驱动轮的改进与模态分析

由于当前掘进机上的链轮在地下使用过程中出现了问题,本文通过建立数学理论建模设计了新的链轮,并用三维建模软件proe进行了实体建模,导入ansys中对其进行静强度和刚度分析,从而对改进的链轮进行了校核,从理论模型和动态仿真两部分说明其合理性,并对合理链轮进行了动力学模态分析,为整个机构设计提供合理依据。     

参数化机械CAD图形支撑软件简介

机械CAD中绘图软件是CAD的底层模块，主要作用是将设计和工程分析的结果以零件图、装配图形式输出。目前，比较成熟的绘图软件一般采用编程式、交互式和参数化绘图方法。编程式采用计算机高级语言、编程方式进行绘图，当一种规格的零件图生成后，只需修改参数值即可获得同结构不同规格的零件图。编程式绘图在提高图纸精度，提供系列化图纸等方面起了很大的作用。但是由于其直观性较差，不能对图纸作逐步修改，导致了交互式给图系统的产生。交互式是目前广泛使用的一种方法，使用者通过用户界面直接与图形打交道，而不必理会计算机内部处…     

AutoCAD中表面粗糙度符号的标注

AutoCAD是Autodesk公司开发的一种大型计算机辅助绘图软件，它功能强大，性能稳定，广泛应用于建筑、机械等设计领域。在机械设计中绘制零件图必须清楚地表达零件精度，而反映机械零件精度的三大指标是尺寸公差、形位公差和表面粗糙度。在AutoCADR１４或R２０００软件中已有尺寸公差、形位公差的标注命令，但表面粗糙度却没有，在对某些零件图表面粗糙度要求较多的情况下，标注零件图的表面粗糙度是一项十分繁琐的工作，笔者经过多年实践，运用插入带属性的表面粗糙度符号图块的方法进行表面粗糙度符号的标注，不仅能提高了标注效率，…     

浪潮夹具CAD系统

浪潮夹具ＣＡＤ系统──主要功能：●基础绘图软件为当今世界最为流行的微机ＣＡＤ软件包──ＡｕｔｏＣＡＤ。●各类机床夹具设计：完成装配图设计，自动生成零件图。●夹紧刀、定位误差的分析计算。●夹具明细表生成，夹具数据库管理。●既可人机交互，也可以函数调用的...     

基于事物特性表的除氧器参数化设计系统

提出了一种基于事物特性表的除氧器参数化设计方法,这种方法是以数据库和模型库为支撑,实现除氧器的智能参数化设计。事物特性表描述了除氧器总体、零部件、标准件等所有参数和属性,组成了一个庞大的专家系统。经验丰富的工程师总结出计算、选型、设计等方法,再加上企业规范组成推理机,通过VB6.0使推理机成为用户操作的计算机对象,实现了从参数计算到结构设计、工艺设计、以及最终生成并完善二维CAD图纸的功能。     

Android手机中基带跟踪数据的导出功能设计

本文主要基于现有Android手机系统框架设计了一种基带跟踪数据导出方案。对方案的总体框架、AP侧的软件流程、CP侧跟踪数据发送流程、串口通信机制的设计进行了详细说明,并给出了方案验证。在由三星公司Exynos4412四核AP芯片和重邮信科公司C6310双模CP芯片组成的手机硬件系统上实现和测试了该方案。实验结果表明,该基带数据导出方案在实际产品中具有良好的可靠性和可行性。     

Data integrity in an IGES description of turned part geometry

There is a growing interest in converting manually drawn engineering drawings into computer databases in a Computer Aided Design (CAD) format such as Initial Graphics Exchange Specification (IGES). This conversion is done by a high resolution scanning device. CAD drawings resulting from the scan-conversion process often contain discontinuities. A draftman using manual drafting equipment may adjust and reposition the ink pen for ease of drawing. This could cause breaks in the drawing, which, though unnoticeable to the human eye, are identified as discontinuities in the electronic scanning process. The subsequent CAD representation may then have broken geometries in place of continuous ones.

The work presented here is aimed at verifying the IGES file representing a scan-converted drawing. If any discontinuities are detected in the lines and arcs in the drawing, the breaks are mended. Algorithms are developed to identify and correct errors in the IGES files.

The algorithms are coded in Common LISP. The program runs on a VAX VMS system and can handle drawings of turned parts. This research is part of a larger project dealing with feature recognition of turned parts. Extension of the procedure to other geometries is straightforward. The program has been tested on some test drawings obtained from a scanning company. The results are very promising.     

A single solution method for converting 2D assembly drawings to 3D part drawings

Although solid models play a central role in modern CAD systems, 2D CAD systems are still commonly used for designing products without complex curved faces. Therefore, an important task is to convert 2D drawings to solid models, and this is usually carried out manually even in present CAD systems. Many methods have been proposed to automatically convert orthographic part drawings of solid objects to solid models. Unfortunately, products are usually drawn as 2D assembly drawings, and therefore, these methods cannot be applied. A further problem is the difficult and time-consuming task of decomposing 2D assembly drawings into 2D part drawings. In previous work, the authors proposed a method to automatically decompose 2D assembly drawings into 3D part drawings, from which 2D part drawings can be easily generated. However, one problem with the proposed method was that the number of solutions could easily explode if the 2D assembly drawings became complex. Building on this work, here we describe a new method to automatically convert 2D assembly drawings to 3D part drawings, generating a unique solution for designers regardless of the complexity of the original 2D assembly drawings. The only requirement for the approach is that the assembly drawings consist of standard parts such as bars and plates. In 2D assembly drawings, the dimensions, part numbers and parts lists are usually drawn, and the proposed method utilizes these to obtain a unique solution.     

能耗曲线在带钢热连轧负荷分配控制中的应用

主要介绍了带钢热连轧厚度控制中采用能耗曲线的方法,对轧机的负荷分配进行分析和设计,详细论述了能耗曲线的建立过程以及运用于实际生产过程中的轧制力分配和辊缝分配的控制方案,并给出了它们各自具体的控制原理、计算公式以及程序框图。该负荷分配方法用于在线,有较好的使用效果。     

A technique for encoding lines and regions in engineering drawings

An improvement to a method of extracting line and region information from technical drawings is presented. A scheme for compressing this information as it is being found is also given. The encoding scheme is based on a combination of run-length codes, direction chain codes, and Huffman codes. It is efficient, requires minimal storage, and achieves favorable compression ratios. Experimental results from four typical line drawings are presented.     

基于Revit的桩基承台自动设计算法

摘 要： 针对 Revit 自有的功能构建建筑信息模型(BIM)效率较低等问题,基于 Revit 二次 开发,在没有桩基承台平面布置 CAD 图的情况下,通过识别由结构分析软件生成的柱(墙)底内 力图的图元信息,提出了一种桩基承台自动设计算法。该方法以 Revit 制作单桩竖向承载力特 征值计算表为基础,在 C#中编写算法程序。根据桩基承台的构造和上部结构的要求自动设计出 桩基承台,并将满足承载力要求的桩基承台准确地布置在相应的柱(墙)下,其显著地提高了桩 基工程建模效率,且为后续工程量计算以及不同桩基础经济性比较提供便利。     

An interdisciplinary heuristic evaluation method for universal building design

This study highlights how heuristic evaluation as a usability evaluation method can feed into current building design practice to conform to universal design principles. It provides a definition of universal usability that is applicable to an architectural design context. It takes the seven universal design principles as a set of heuristics and applies an iterative sequence of heuristic evaluation in a shopping mall, aiming to achieve a cost-effective evaluation process. The evaluation was composed of three consecutive sessions. First, five evaluators from different professions were interviewed regarding the construction drawings in terms of universal design principles. Then, each evaluator was asked to perform the predefined task scenarios. In subsequent interviews, the evaluators were asked to re-analyze the construction drawings. The results showed that heuristic evaluation could successfully integrate universal usability into current building design practice in two ways: (i) it promoted an iterative evaluation process combined with multi-sessions rather than relying on one evaluator and on one evaluation session to find the maximum number of usability problems, and (ii) it highlighted the necessity of an interdisciplinary ad hoc committee regarding the heuristic abilities of each profession. A multi-session and interdisciplinary heuristic evaluation method can save both the project budget and the required time, while ensuring a reduced error rate for the universal usage of the built environments.     

How to Render Frames and Influence People

Rendering systems generally treat the production of images as an objective process governed by the laws of physics. However, perception and understanding on the part of viewers are subjective processes influenced by a variety offactors. For example, in the presentation of architectural drawings, the apparent precision with which the drawings are made will affect whether the viewer considers the design as part of a preliminary design or as part of a final polished project, and to some extent the level of confidence the viewer has in the encoded information. In this paper we develop techniques for rendering images in a way that differs from the usual photorealistic or wire-frame output of renderers. In particular, our techniques allow a user to adjust the rendering of a scene to produce images using primitives with variable degrees of precision, from approximations that resemble vague “five-minute-sketches” to more mature but still hand-drawn images. We provide a theoretical framework for analysing the information flow from the computer to the user via such images. Finally, we describe the design and implementation of a prototypical renderer and show examples of its output.