逆向工程与快速成型技术应用研究

阐述了逆向工程与快速成型技术的基本概念,分析了逆向工程数据处理中的主要内容和逆向工程的关键技术与解决办法,介绍了逆向工程在快速成型中的应用.逆向工程与快速成型技术的结合,将使复杂型面的产品设计开发和快速成型周期进一步缩短.     

逆向工程技术与快速成型技术在新产品开发中的应用

简要介绍了逆向工程技术和快速成型技术的基本概念、特点及关键技术，并且运用集成和系统的思想阐述了逆向工程技术与快速成型技术之间的关系。通过利用逆向工程软件Imageware对手机点云数据进行数据处理、曲面重构来举例说明逆向工程技术与快速成型技术在新产品开发中的应用。     

逆向工程与快速成型技术的应用

介绍了逆向工程技术和快速成型技术的定义和逆向工程与快速成型的一般流程。并通过一个简单球面的反求工艺实例,阐述了逆向工程中数据采集、产品建模以及产品快速成型的一般过程。从而证明了逆向工程技术是一个多领域、多学科的系统工程,是基于新的设计思想和方法,在计算机技术、数控测量技术和CAD/CAM技术发展基础上产生的一项新技术,能广泛运用于模具行业,并有一定的影响力。本文证实了逆向工程技术和快速成型技术的前沿性和可靠性,并展望了逆向工程技术与快速成型应用的前景。     

基于快速成型的逆向工程技术集成

逆向工程与快速成型技术是CAD/CAM技术的重要组成部分。运用集成和系统的思想,阐述基于快速成型的逆向工程流程,探讨了逆向工程整体框架的关键技术。逆向工程的关键技术包括数据采集、数据处理、曲面重构、再设计、曲面品质分析及优化等。     

快速成型技术在医学上的应用

随着计算机技术的快速发展,三维重建和快速成型技术逐步应用于医学领域.结合逆向工程及快速成型技术的基本原理,重点阐述了逆向工程及快速成型技术在先天性单侧唇裂三维模型的重建、面容多发性骨折缺损骨和下颌骨缺损三维模型重建等医学上的应用,并简单介绍了快速成型技术在现代医学应用上的重要意义,最后根据快速成型技术的特点,提出了快速成型技术在现阶段存在的问题及其以后在文化艺术,航天航空及家电行业等领域的发展前景.     

快速制造技术在快速逆向工程中的应用

阐述了快速逆向工程的概念及实现步骤,通过对目前技术上比较成熟的几种快速成型工艺的介绍,总结了快速成型技术的特点及其快速逆向工程中的应用,最后提出了快速制造技术将向新型复合材料、高效低在本、高精度方向发展。     

基于逆向工程与快速成型技术的产品再设计研究

通过具体实例阐述了利用逆向工程和快速成型技术完成产品再设计的一般步骤,阐明基于逆向工程与快速成型技术的产品再设计的实用性与优越性。     

快速成型及快速制模技术

介绍快速成型技术的工艺过程，逆向工程数据处理流程，也介绍了快速制模技术的几种方法。     

逆向工程技术在绿色再制造工程中的应用

通过对基于弧焊工艺的金属直接成型再制造系统的研究。提出将逆向工程技术和绿色再制造成型技术相结合破损零件快速修复方法。该方法利用逆向工程技术快速获取破损零件的三维CAD模型,并根据零件的3D模型实现了对破损部位的精确定位,从而进行受损部位的精确修复和金属直接成型再制造,解决了基于弧焊工艺的金属直接成型方法对破损部位的精确定位问题。     

基于逆向工程的支架零件优化设计及快速成型

对结构复杂的支架类零件进行逆向建模及优化设计,并提出了一条基于逆向工程的产品优化设计及快速成型的路线。将三维扫描技术、点云预处理技术、参数化逆向建模技术、有限元分析技术和快速成型技术相结合,对重构后的模型快速实现再设计,缩短研发周期,便于定制化生产和工业化改造。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.