多材料零件3D打印技术现状及趋势

多材料零件(也称异质材料零件)由于兼顾控形、控材和控性等优越特性,在航空航天、特种工业、医学工程等领域具有广阔市场应用前景,也日益成为国内外3D打印领域的研究热点。介绍了多材料零件3D打印技术涉及的2个关键问题:多材料零件的建模方法和多材料零件的3D打印成型技术。结合多材料零件3D打印技术的应用与发展趋势,分析了多材料零件3D打印研发过程中亟待解决的关键技术。     

软体机器人3D打印制造技术研究综述

基于弹性、软质材料的软体机器人变形能力强、人-机-环境共融性好,在工业、医疗、家庭服务等众多领域具有良好的应用前景.软体机器人是本体、驱动、感知等高度集成的新型机电一体化智能系统.软体机器人呈现的诸多新特征给机器人领域的制造、驱动、建模、感知及控制等技术带来了全新的挑战.软质材料3D打印技术与装备的快速发展为软体机器人制造实现提供了有力支撑.首先,介绍了主流软质材料3D打印技术的基本原理与特点,包括熔融沉积成形、直接墨水书写、喷墨打印、光固化成型和选择性激光烧结3D打印技术.然后,针对软体机器人一体化制造发展需求,介绍了多材料3D打印、4D打印、嵌入式3D打印等前沿技术.最后,介绍和分析了国内外基于3D打印技术的软体驱动器和柔性传感器经典案例,结合控制-传感-驱动一体化的类生物结构软体机器人发展需求,预测了未来3D打印技术主要发展趋势与技术挑战.     

工业级3D打印机调研

随着3D打印技术的飞速发展,在工业、电子、军事、航空航天、医疗、建筑等领域的应用日益广泛,文中着重介绍了工业级3D打印机及3D打印材料在工业领域的应用情况。     

3D打印技术对衡器产品开发的影响

3D打印技术是一种快速成型技术,以电脑设计的模型文件为基础,运用粉末状金属或塑料等可粘合材料,通过逐层打印的方式来构造物体的技术。从而缩短产品的研制周期,提高生产率和降低生产成本。本文介绍了3D打印技术及3D打印技术对衡器产品开发中的影响。     

3D打印技术在医学领域的应用与展望

首先简单介绍了自生物制造概念提出以来,3D打印技术在医学领域的应用已取得的进展;然后总结和重点介绍了3D打印技术在构建医学模型、人工骨骼,制造生物器官、牙齿、可控释放药物以及整形美容等方面的应用;最后对3D打印技术在医学领域的发展趋势进行了预测。     

3D打印控制系统研究综述

3D打印技术因其具有可以成型复杂几何模型、加工过程操作简单的特点,因此在加工制造业、工业设计及医疗行业等生产领域均有着广泛应用.对3D打印控制系统主要部分的研究现状进行介绍,包括运动轨迹的规划及运动控制策略的优化、温度控制策略方案的优劣等控制部分;综述了现有的控制系统架构及控制方法,对比总结了各自的特点;最后,梳理总结了控制系统存在的一些共性问题,并对未来发展进行了展望,包括优化控制方案、提升过程控制技术、增强系统功能多样性及智能化程度.     

金属3D打印技术的发展分析

随着塑料材料3D打印技术相对成熟,金属3D打印技术凸显出巨大的发展潜力,成为当今快速成型领域重要的发展方向和研究热点。且3D打印技术工业化的应用需求增加,对材料的力学性能提出了更高的要求,因此金属材料的3D打印顺势而生。文中对金属3D打印技术的分类、当前校企研究现状、发展瓶颈、发展方向等进行论述,旨在为普及和推广3D打印技术提供一定帮助。     

生物医学领域3D打印技术的发展及展望

3D打印技术是一种基于计算机辅助制造的快速成型技术,其在多个领域的应用均展现出极大的优势。本文对近年来3D打印技术在生物医学领域的个性化应用,包括在生物医用支架材料、人造活体组织器官和组织器官模型制作以及药物制作与筛查方面的研究进行综述,并对3D打印技术在生物医学领域中的应用前景和挑战作出展望,为3D打印技术在生物医学领域的深入研究和广泛应用提供参考。     

3D打印技术在医疗领域的应用价值与展望

首先介绍了3D打印技术的突出优势、常用的3D打印工艺类型及各自的优缺点,然后阐述了3D打印在国内外医疗领域的应用价值及研究现状,并就该技术发展过程中存在的问题以及不同3D打印工艺在医疗领域的主要应用方向进行了评述,最后指出了3D打印技术在医疗领域由推广走向成熟过程中有待攻克的难点,并展望了该技术在医疗行业的广阔发展前景。     

金属3D打印技术工艺探索研究

3D打印技术是在原材料的基础上选用层层叠加的形式促使其成型的一种增材制造新技术。为了实现产品性能指标提升、技术创新,现阶段金属3D打印技术在汽车制造、航空航天、生物医疗等领域获得了推广应用。结合当前金属3D打印技术的研究现状展开论述,阐述不同技术的实践应用,明确金属3D打印技术的发展趋势,以期为金属3D打印工艺提供理论依据和实践应用参考。     

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.     

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....     

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。     

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.