Surfacer在车身覆盖件逆向工程中的应用

介绍了逆向工程的含义及工作流程 ,阐述了车身覆盖件的三维点数据采集的过程及原理 ,讨论了利用逆向工程CAD软件Surfacer对车身覆盖件点云数据处理并进行曲面创建及造型的过程。

Surfacer二次开发在逆向工程设计中的应用

使用Scoll语言对Surfacer进行二次开发,可以令重复性、互换性很强的自动化工程变得更加容易,通过修改Surfa-cer启动目录下的菜单定义文件,Surfacer的用户界面也会相应改变。示例一段可以实现自动排列义齿的Scoll语言程序,将Scoll命令语言在Surfacer二次开发中的应用做了详细的讲解,包括自定义函数的构造,菜单文件的修改等。

Surfacer在模具CAD/CAM反求造型中的应用研究

本文就涡轮反求造型的实例, 采用Surfacer软件规划出由实物转化为工程 CAD资料的一般流程。在深入分析点云数据的矢量方向基础上, 采用积累弦长参数化方案实现点云的参数化; 根据最小二乘法曲线拟合原理, 修改曲线参数获得高品质曲线; 并重点论述了点云处理、曲线生成、建构曲面的方法, 为模具加工提供了建构高品质CAD模型的有效途径。

基于Surfacer和CATIA的电话机模型重建

实物的CAD模型重建是逆向工程的关键技术。目前逆向工程专业软件有十几种,但与传统的CAD/CAM软件相比在造型技术等方面仍有不足。因此,提出一种基于Surfacer和CATIA的模型重建方法,充分利用两个软件的优势,成功地完成了电话的模型重建。

Surfacer在逆向工程中的应用

在工业产品的设计过程中,为了使产品更为美观或实现某些特殊的性能,往往要求其外表面光顺而富于变化。通常此类产品是由复杂的自由曲面拼合而成的,由于其在概念设计阶段很难用严密统一的数字语言来描述,故而许多产品的初始模型必须对事先造出的泥制或木制的模型进行测量,再以此为依据,反求出实物模型。这种以实物模型为依据来生成几何模型的设计方法即为逆向工程。图1给出了一个比较完整的逆向工程的结构示意图。

逆向工程中基于Solid Edge与Surfacer的产品三维重构

随着工业技术的进步以及经济的发展,产品的工业设计已逐渐受到重视.一些具有美工背景的设计师用手工方式塑造出产品模型,然后通过三维测量来建立模型的CAD图形文件.

Surfacer在曲面重构中应用研究

针对典型样件分析了由样件点云到曲面实体生成的处理方法,重点讨论了曲面点云的处理、定位操作,实现了轮廓曲线的生成和曲面的重构,通过曲面的延伸和修剪处理,完成由点云到曲面实体的重构,对曲面和点云信息进行了误差比较,最后得出结论。

利用Surfacer软件进行自由曲面的数字化检测

对于CAD模型已知的自由曲面精度检测,存在被测曲面与标准CAD模型难以配准和定量比较的问题,本文提出利用逆向工程软件Surfacer的定位与比较功能进行自由曲面的在线检测,实验结果表明所提方法是可行的,为复杂自由曲面零件的在线检测开辟了一条有效的途径。

基于Surfacer的点云数据的预处理研究

“点云”的预处理研究,包括平滑和拓扑关系的建立。利用反求软件—Surfacer,对“点云”进行了平滑,然后直接从空间入手,从一般性的角度来说明了点云数据的三角剖分的算法,建立数据之间的拓扑关系。文中最后指出下一步的工作。

基于Surfacer和UG的机电产品反求设计

应用Surfacer和UG软件,对反求工程中基于NURBS的曲线、曲面重构进行了研究。结合实例,讨论了从点云数据到实体生成具体实现的方法,并提出由多个面沿某方向构建点云-由点云构线-最后同时构面的思想。

应用Surfacer和UG的复杂曲面构建过程的探讨

通过对摩托车油箱上壳表面的数字化构建研究,介绍了surfacer和UG软件对测量的数据进行CAD模型的构建技术和方法。

Surfacer二次开发在叶片锻件检测中的应用

简要介绍了逆向软件Surfacer的内外部开发模式,并利用其二次开发功能,结合叶片检测技术,研究开发了针对叶片锻件的检测系统。通过示例程序介绍了程序编写方法。经应用测试,系统可以顺利完成测量工作,界面简洁清晰,便于操作,与传统测量方法相比具有速度快、精度高等特点。该系统的应用对逆向软件在实际生产中的发展有着很大的推动作用。

STUDY ON MEASUREMENT OF WOOD SURFACEROUGHNESS BY COMPUTER VISION

The working processes, machining devices and tools, cutting amount, consumption of materials, productivity and quality of products are directly affected by wood surface roughness. This paper gives an extensive review of methods used previously to measure wood surface roughness, and concludes that computer vision is the most suitable technique. The preliminary study shows that computer vision method has the advantages of a noncontact, three-dimensional measurement, high speed and well correlates with stylus tracing method. This method can be used in classification and in-time measurement of wood surface roughness after being improved.

Effects of Chairside Polishing and Brushing on SurfaceRoughness of Acrylic Denture Base Resins

The effects of 3 chairside polishing kits and mechanical brushing on the surface roughness of 3 different acrylic denture base resins were compared. Acrylic denture base resins （auto-polymerizing, heat-polymerizing, injected heat-polymerizing resins） were examined after a tungsten carbide bur, and after chairside polishing using 3 polishing kits and pumice. The specimens were subjected to mechanical brushing using a wear tester to simulate 30 000 strokes of brushing. The surface roughness of the acrylic denture base resin specimens was measured using a contact pro-filometer. After the test, the random polished acrylic resins were evaluated by scanning electron mi-croscopy （SEM） and atomic force microscopy （AFM）. Acrylic denture base resins polished using the 3 types of polishing kits had a smoother surface than those finished with the tungsten carbide bur （p〈0.05）. The surface of the resin polished by a TC cutter exceeded the Ra of 0.2 μm （p〈0.05）. The auto-polymerizing resin showed a significantly higher surface roughness than the heat-polymerizing resin and injected heat-polymerizing resin （p〉0.05）. In the case of polishing step wise, there was almost no change in surface roughness after brushing （p〉0.05）.

忘掉SurfaceRT ASUS VivoTabSmart ME400C

不少人问我，买个Surface是否就能从传统Windows电脑平滑过渡到Windows平板？某种程度上是，不过那应该是指昂贵的SurfacePro，SurfaceRT还不行。

Research status and prospects of the fractal analysis of metal material surfaces and interfaces

As a mathematical analysis method,fractal analysis can be used to quantitatively describe irregular shapes with self-similar or self-affine properties.Fractal analysis has been used to characterize the shapes of metal materials at various scales and dimensions.Conventional methods make it difficult to quantitatively describe the relationship between the regular characteristics and properties of metal material surfaces and interfaces.However,fractal analysis can be used to quantitatively describe the shape characteristics of metal materials and to establish the quantitative relationships between the shape characteristics and various properties of metal materials.From the perspective of two-dimensional planes and three-dimensional curved surfaces,this paper reviews the current research status of the fractal analysis of metal precipitate interfaces,metal grain boundary interfaces,metal-deposited film surfaces,metal fracture surfaces,metal machined surfaces,and metal wear surfaces.The relationship between the fractal dimensions and properties of metal material surfaces and interfaces is summarized.Starting from three perspectives of fractal analysis,namely,research scope,image acquisition methods,and calculation methods,this paper identifies the direction of research on fractal analysis of metal material surfaces and interfaces that need to be developed.It is believed that revealing the deep influence mechanism between the fractal dimensions and properties of metal material surfaces and interfaces will be the key research direction of the fractal analysis of metal materials in the future.

3D Printing of Tough Hydrogel Scaffolds with Functional Surface Structures for Tissue Regeneration

Hydrogel scaffolds have numerous potential applications in the tissue engineering field.However,tough hydrogel scaffolds implanted in vivo are seldom reported because it is difficult to balance biocompatibility and high mechanical properties.Inspired by Chinese ramen,we propose a universal fabricating method(printing-P,training-T,cross-linking-C,PTC&PCT)for tough hydrogel scaffolds to fill this gap.First,3D printing fabricates a hydrogel scaffold with desired structures(P).Then,the scaffold could have extraordinarily high mechanical properties and functional surface structure by cycle mechanical training with salting-out assistance(T).Finally,the training results are fixed by photo-cross-linking processing(C).The tough gelatin hydrogel scaffolds exhibit excellent tensile strength of 6.66 MPa(622-fold untreated)and have excellent biocompatibility.Furthermore,this scaffold possesses functional surface structures from nanometer to micron to millimeter,which can efficiently induce directional cell growth.Interestingly,this strategy can produce bionic human tissue with mechanical properties of 10 kPa-10 MPa by changing the type of salt,and many hydrogels,such as gelatin and silk,could be improved with PTC or PCT strategies.Animal experiments show that this scaffold can effectively promote the new generation of muscle fibers,blood vessels,and nerves within 4 weeks,prompting the rapid regeneration of large-volume muscle loss injuries.

Preparation and Performance of Ternary Early Strength Agent and Quercetin Composite Cement Sealing Material

A ternary early-strengthening agent consisting of calcium formate+triethanolamine+lithium sulfate was compounded with quercetin to shorten the setting time of cementitious materials while ensuring their early strength.The optimum ratio of the three early-strengthening agents was determined as 0.5%calcium formate+0.04%triethanolamine+0.4%lithium sulfate by response surface methodology.The effects of the ternary early-strengthening agent composed of calcium formate+triethanolamine(TEA)+lithium sulfate on cementitious pore sealing materials under the synergistic effect of quercetin were studied by means of the performance tests of compressive strength,fluidity,and setting time,and the microstructural characterizations of X-ray powder diffractometer(XRD),thermogravimetry(TG-DSC)and scanning electron microscopy(SEM).The study shows that the synergistic effect of ternary early-strengthening agent and quercetin forms a multi-performance composite admixture for cementitious materials.The best performance was obtained with the compounding scheme of 0.5%calcium formate+0.04%triethanolamine+0.4%lithium sulfate ternary early-strengthening agent and 0.05%quercetin.The compressive strength of 1,3,7,and 28 d are 94.8%,39.8%,42%,and 28%higher than those of the blank group,respectively.The initial time and final setting time are 41 and 57 minutes,respectively.According to the microscopic analysis,the network and fibrous C-S-H gels generated by ternary early-strengthening agents are attached to the surface promoted by quercetin,which forms skeleton support while thickening and solidifying the cement slurry,which enhances the early compressive strength of the cement-based materials.

Microstructure and Wear/corrosion Resistance of Stainless Steel Laser-alloyed with Mn+W_(2)C, Mn+NiWC and Mn+SiC

In-situ formed high Mn steel coating reinforced by carbides was formed by laser surface alloying(LSA).Laser alloyed layers on 1Cr18Ni9Ti steel with Mn+W_(2)C(specimen A),Mn+NiWC(specimen B)and Mn+SiC(specimen C)powders were fabricated to improve the wear and corrosion behavior of 1Cr18Ni9Ti steel blades in high speed mixers.Microstructure evolution,phases,element distribution,microhardness,wear and corrosion behavior of the laser alloyed layers were investigated.Results indicated that high Mn steel matrix composites with undissolved W_(2)C,WC and other in-situ formed carbides were formed by LSA with Mn+W_(2)C and Mn+NiWC while SiC totally dissolved into the high Mn matrix when adding Mn+SiC.Ni as the binding phase in Ni-WC powder decreased the crack sensitivity of the alloyed layer as compared with the addition of W_(2)C powder.An improvement in average microhardness was achieved in the matrix in specimen A,B and C,with the value of 615,602 and 277 HV_(0.5),while that of the substrate was 212 HV_(0.5).The increase of microhardness,wear and corrosion resistance is highly corelated to microstructure,formed phases,type and content of carbides,micro-hardness and toughness of the alloyed layers.

Crystallization Modulation and Holistic Passivation Enables Efficient Two‑Terminal Perovskite/CuIn(Ga)Se_(2)Tandem Solar Cells

Two-terminal(2-T)perovskite(PVK)/CuIn(Ga)Se_(2)(CIGS)tandem solar cells(TSCs)have been considered as an ideal tandem cell because of their best bandgap matching regarding to Shockley–Queisser(S–Q)limits.However,the nature of the irregular rough morphology of commercial CIGS prevents people from improving tandem device performances.In this paper,D-homoserine lactone hydrochloride is proven to improve coverage of PVK materials on irregular rough CIGS surfaces and also passivate bulk defects by modulating the growth of PVK crystals.In addition,the minority carriers near the PVK/C60 interface and the incompletely passivated trap states caused interface recombination.A surface reconstruction with 2-thiopheneethylammonium iodide and N,N-dimethylformamide assisted passivates the defect sites located at the surface and grain boundaries.Meanwhile,LiF is used to create this field effect,repelling hole carriers away from the PVK and C60 interface and thus reducing recombination.As a result,a 2-T PVK/CIGS tandem yielded a power conversion efficiency of 24.6%(0.16 cm^(2)),one of the highest results for 2-T PVK/CIGS TSCs to our knowledge.This validation underscores the potential of our methodology in achieving superior performance in PVK/CIGS tandem solar cells.