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3D打印与硅橡胶浇注成型快速批量加工螺杆 被引量:1
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作者 肖建华 高延峰 《塑料工业》 CSCD 北大核心 2017年第7期61-64,共4页
首先使用CAD软件进行螺杆模型设计,借助3D打印技术分段加工出复杂螺杆模型;其次使用液态双组分硅橡胶浇注成型制备螺杆模具;最后使用透明热固性聚氨酯(PU)材料浇注硅胶模具,从而实现单个螺杆模型的快速制造、批量复型,美化模型、减少模... 首先使用CAD软件进行螺杆模型设计,借助3D打印技术分段加工出复杂螺杆模型;其次使用液态双组分硅橡胶浇注成型制备螺杆模具;最后使用透明热固性聚氨酯(PU)材料浇注硅胶模具,从而实现单个螺杆模型的快速制造、批量复型,美化模型、减少模型设计和加工成本。采用粗糙度测量仪对3D打印螺杆及批量浇注螺杆进行了表面粗糙度测试。研究结果表明:双组分PU材料浇注出的螺杆模型比3D打印螺杆具有更低的表面粗糙度,加工出的模型表面光滑、成型加工简单快捷。3D打印与硅橡胶浇注成型相结合的这种加工方法为各种塑料模型的开发、快速批量加工提供了一种简便的方法。 展开更多
关键词 cad模型设计 3D打印 硅橡胶制模 浇注成模 快速批量加工
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利用CAD模型的不完全扫描CT图像重建 被引量:3
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作者 余浩松 邹永宁 +2 位作者 张智斌 姚功杰 周日峰 《光学学报》 EI CAS CSCD 北大核心 2021年第6期101-111,共11页
工业计算机断层成像(CT)扫描大尺寸和高密度工件时,会出现穿不透、扫描角度有限导致的投影数据不完备、重建伪影严重等问题。基于此,提出一种将工件的CAD设计模型作为先验知识,来实现该类对象的有限角CT重建优质图像的方法。由工件CT扫... 工业计算机断层成像(CT)扫描大尺寸和高密度工件时,会出现穿不透、扫描角度有限导致的投影数据不完备、重建伪影严重等问题。基于此,提出一种将工件的CAD设计模型作为先验知识,来实现该类对象的有限角CT重建优质图像的方法。由工件CT扫描的断层位置计算CAD模型对应的分层位置,并得到模型的像素截面;根据CT系统X射线能量和模型中各部分材质,确定和生成一幅衰减系数图像,并将其配准到一幅零灰度图像中,得到先验图像;最后对扫描投影数据进行SART+TVM+PRIOR算法重建,得到重建图像。仿真实验和实际工件扫描实验的结果显示,加入先验图像后重建的图像质量要远远优于未加入先验图像的重建结果,边缘结构更加清晰,并极大地减少了伪影。 展开更多
关键词 成像系统 工业CT 投影数据不完备 cad设计模型 先验图像 图像重建
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Science Letters:Mask synthesis and verification based on geometric model for surface micro-machined MEMS 被引量:1
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作者 李建华 刘玉生 高曙明 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第9期1007-1010,共4页
Traditional MEMS (microelectromechanical system) design methodology is not a structured method and has become an obstacle for MEMS creative design. In this paper, a novel method of mask synthesis and verification fo... Traditional MEMS (microelectromechanical system) design methodology is not a structured method and has become an obstacle for MEMS creative design. In this paper, a novel method of mask synthesis and verification for surface micro-machined MEMS is proposed, which is based on the geometric model of a MEMS device. The emphasis is focused on synthesizing the masks at the basis of the layer model generated from the geometric model of the MEMS device. The method is comprised of several steps: the correction of the layer model, the generation of initial masks and final masks including multi-layer etch masks, and mask simulation. Finally some test resuhs are given. 展开更多
关键词 MEMS cad Geometric model Layer model Mask synthesis Surface micromachining
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A mathematical model of symmetry based on mathematical definition 被引量:3
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作者 刘玉生 杨将新 +1 位作者 吴昭同 高曙明 《Journal of Zhejiang University Science》 CSCD 2002年第1期24-29,共6页
Tolerance is imperative for seamless integration of CAD/CAM(Computer Aided Disign/Computer Aided Manufacture) which is just a text attribute and has no semantics in present CAD systems. There are many tolerance types,... Tolerance is imperative for seamless integration of CAD/CAM(Computer Aided Disign/Computer Aided Manufacture) which is just a text attribute and has no semantics in present CAD systems. There are many tolerance types, the relations between which are very complicated. In addition, the different principles of tolerance make study of tolerance difficult; and there may be various meanings or interpretation for the same type of tolerance because of the literal definition. In this work, latest unambiguous mathematical definition was applied to study, explain and clarify: (1) the formation and representation of tolerance zone, and (2) the formation and representation of variational elements; after which, the mathematical models of symmetry of different tolerance principles and different interpretations were derived. An example is given to illustrate the application of these models in tolerance analysis. 展开更多
关键词 mathematical definition symmetry tolerance mathematical model cad/CAM production engineering
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Feature-based multiresolution techniques for product design
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作者 LEE Sang Hun LEE Kunwoo 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2006年第9期1535-1543,共9页
3D computer-aided design (CAD) systems based on feature-based solid modelling technique have been widely spread and used for product design. However, when part models associated with features are used in various downs... 3D computer-aided design (CAD) systems based on feature-based solid modelling technique have been widely spread and used for product design. However, when part models associated with features are used in various downstream applications, simplified models in various levels of detail (LODs) are frequently more desirable than the full details of the parts. In particular, the need for feature-based multiresolution representation of a solid model representing an object at multiple LODs in the feature unit is increasing for engineering tasks. One challenge is to generate valid models at various LODs after an arbitrary rearrangement of features using a certain LOD criterion, because composite Boolean operations consisting of union and subtraction are not commutative. The other challenges are to devise proper topological framework for multiresolution representation, to suggest more reasonable LOD criteria, and to extend applications. This paper surveys the recent research on these issues. 展开更多
关键词 MULTIRESOLUTION Level of detail (LOD) FEATURE SOLID NON-MANIFOLD
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Technical illustration based on 3D CSG models
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作者 耿卫东 丁磊 +1 位作者 余宏锋 潘云鹤 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第5期469-475,共7页
This paper presents an automatic non-photorealistic rendering approach to generating technical illustration from 3D models. It first decomposes the 3D object into a set of CSG primitives, and then performs the hidden ... This paper presents an automatic non-photorealistic rendering approach to generating technical illustration from 3D models. It first decomposes the 3D object into a set of CSG primitives, and then performs the hidden surface removal based on the prioritized list, in which the rendition order of CSG primitives is sorted out by depth. Then, each primitive is illustrated by the pre-defined empirical lighting model, and the system mimics the stroke-drawing by user-specified style. In order to artistically and flexibly modulate the illumination, the empirical lighting model is defined by three major components: parameters of multi-level lighting intensities, parametric spatial occupations for each lighting level, and an interpolation method to calculate the lighting distribution over primitives. The stylized illustration is simulated by a grid-based method, in which we ‘fill’ the desirable pictorial units into the spatial occupation of CSG primitives, instead of “pixel-by-pixel” painting. This region-by-region shading facilitates the simulation of illustration styles. 展开更多
关键词 Non-photorealistic rendering (NPR) Technical illustration Expressive rendering cad
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Control method for semi-active suspension based on virtual prototype
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作者 梁宇 《Journal of Chongqing University》 CAS 2005年第1期6-8,共3页
The simple dynamic model is often adopted to deal with control questions in research on semi-active suspension. The model has more theoretic meanings than authentic ones because of difference between practical and phy... The simple dynamic model is often adopted to deal with control questions in research on semi-active suspension. The model has more theoretic meanings than authentic ones because of difference between practical and physical models. The virtual prototype has remarkable advantages in its application simulation processes. It is not only faster and more veracious, but also of better visualization of the simulation results. 展开更多
关键词 semi-active suspension virtual prototype linear-quadratic regulator (LQR) control
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Design and experimental study of the SPKM165, a five-axis serial-parallel kinematic milling machine 被引量:6
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作者 XIE FuGui LIU XinJun +1 位作者 ZHANG Hui WANG JinSong 《Science China(Technological Sciences)》 SCIE EI CAS 2011年第5期1193-1205,共13页
A five-axis serial-parallel kinematic milling machine, the SPKM 165, is introduced. This machine consists of a three-degree of-freedom parallel module and a two-degree-of-freedom serial table. The SPKM 165 is capable ... A five-axis serial-parallel kinematic milling machine, the SPKM 165, is introduced. This machine consists of a three-degree of-freedom parallel module and a two-degree-of-freedom serial table. The SPKM 165 is capable of five-face machining. A discussion of the inverse kinematics of the five-axis control is provided. A dimensional synthesis procedure is presented in terms of motion/force transmissibility. Finite-element analysis was used to evaluate the stiffness of a CAD model before the machine was manufactured. Kinematic calibration was implemented to improve the accuracy of the end effector. The results of a calibration experiment are presented. The stiffness of the developed machine was then measured. Milling experiments were conducted, and the test piece showed that the developed machine has satisfactory performance. 展开更多
关键词 serial-parallel kinematic machine dimension synthesis stiffness evaluation kinematic calibration
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