共查询到19条相似文献,搜索用时 109 毫秒
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基于STL模型支撑生成算法的研究 总被引:4,自引:0,他引:4
针对快速成型制造中须对零件加支撑的需求,提出一种新的支撑生成方法。它首先提取零件待支撑区域的关键特征(如悬吊点、下棱线、待支撑下表面的轮廓线等),同时指出各种支撑的基本构件实质就是单边对应的多边形支撑面,并采用了局部斜板支撑的方案实现其生成算法,在此基础上生成零件的特征支撑;然后采用对生成的特征支撑STL模型分层后分区扫描填充加强支撑线来实现对待支撑下表面内部区域的有效支撑。应用表明:该方法实现了对成型零件关键特征的准确支撑和对待支撑面域的有效支撑,生成支撑效果良好。 相似文献
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一种检验STL文件正确性的新方法 总被引:3,自引:1,他引:2
在快速成型技术中,从CAD系统中生成的STL模型常会包含多种错误,在切片之前必须对相应的STL文件进行正确性检验。针对上述问题,提出了一种检验STL文件正确性的新方法,该方法操作方便,界面友好。 相似文献
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快速成型技术是一种基于离散/堆积成型原理的制造方法,它是在计算机的控制与管理下,根据零件的CAD模型,采用材料精确堆积的方法制造原型或零件的.目前在快速成型技术中,由于成型机的数据接口问题,通常在切片之前需要将CAD模型转换成STL模型,而STL模型的某些区域存在冗余的三角形,这些三角形的存在增加了切片时候的求交运算量.通过剔除部分狭长的钝角三角形,实现了对STL模型的合理优化,节省了文件存储空间和后续数据处理时间,具有一定的工程意义. 相似文献
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光固化快速成形自动支撑技术研究 总被引:9,自引:1,他引:8
对光固化快速成形中自动支撑问题进行了研究,提出了基于STL模型的待支撑特征识别方法,实现了对待支撑面、悬吊线和悬吊点的提取。根据待支撑特征投影区域的几何特征,将其分为细小区域、细长区域以及环形区域等,针对各类区域的形状特点采用不同的填充算法进行二维支撑填充,提出了三点法确定支撑的生长起始点和终止点的方法,开发出了支撑自动生成软件。实际应用表明该技术可以解决人工加支撑时由于支撑不合理所造成的制作失败及精度降低等问题,节省了Stereolithography加工时的数据预处理时间,提高了快速成形的效率。 相似文献
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快速成形中STL模型的自动修复方法与软件研究 总被引:3,自引:1,他引:2
STL数据模型是当今商用RP系统广泛采用的CAD到RP的数据接口,已成为RP工业界的事实标准。由于STL数据格式本身的缺陷、CAD造型过程中的人为错误以及CAD模型表面三角化方法所存在的问题,致使得到的STL文件所表示的面化数据模型常出现错误,导致RP后续的切片、加工过程不能正常进行。在分析STL模型常见错误的基础上,提出了相应的自动诊断和修复的方法,基于VisualC++6.0研制开发了STL模型自动修复的软件系统。 相似文献
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Improved intermediate point curve model for integrating reverse engineering and rapid prototyping 总被引:1,自引:1,他引:0
V. K. Kumbhar P. M. Pandey P. V. M. Rao 《The International Journal of Advanced Manufacturing Technology》2008,37(5-6):553-562
Direct integration of reverse engineering and rapid prototyping removes two intermediate steps of surface fitting from point
cloud data and STL file generation from CAD models. Therefore errors introduced due to surface fitting and triangulations
are eliminated and also the process of STL data validation and repair is avoided. Intermediate point based curve model (IPCM)
method is one of the promising approaches for direct integration of reverse engineering and rapid prototyping however this
approach has the limitation that it cannot handle objects, which result in multiple contoured slices. Moreover, IPCM based
method is implemented with layers of constant thickness slices, and adaptive slicing with this method is not attempted. The
present work is an attempt towards improving the capabilities of IPCM based method by overcoming the above-mentioned two limitations.
The new system developed here has been tested on many parts, which demonstrates the capability of the proposed system.
An erratum to this article can be found at 相似文献
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Generation of an STL File from 3D Measurement Data with User-Controlled Data Reduction 总被引:6,自引:0,他引:6
Y. H. Chen C. T. Ng Y. Z. Wang 《The International Journal of Advanced Manufacturing Technology》1999,15(2):127-131
Reverse engineering is a methodology for constructing com-puter- aided design (CAD) models of physical parts by digitising
an existing part, creating a computer model and then using it to manufacture the component. When a digitised part is to be
manufactured by means of rapid prototyping machines such as stereolithography apparatus (SLA) and selective laser sintering
equipment (SLS), etc., it is not necessary to construct the CAD model of a digitised part. This can be achieved by the proposed
novel method which can construct an STL file (the de facto file format for rapid prototyping machines) directly from digitised
part data. Furthermore, the STL file can be constructed with a significant data reduction at the users’ discretion. 相似文献
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一种基于STEP的CAD模型直接分层方法 总被引:1,自引:0,他引:1
提出了一种基于产品模型数据交换标准的3维计算机辅助设计实体模型直接分层方法,零件的原始计算机辅助设计模型以产品模型数据交换标准中性文件的格式输入分层系统,系统提取其几何拓扑信息并重建计算机内部几何模型。用户选择零件的制作方向并指定分层厚度后,系统自动对计算机辅助设计模型进行直接分层,分层结果可直接送到各种快速成型系统加工。基于产品模型数据交换标准的计算机辅助设计模型直接分层不依赖任何特定的计算机辅助设计系统,通用性、灵活性好,而且产品模型数据交换标准文件的数据量大大小于STL文件,有利于网络化设计与制造环境下的数据传输与交换。 相似文献
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基于空间微四面体的异质材料零件建模方法 总被引:1,自引:1,他引:0
当前以均质材料为设计前提的大多数商用计算机辅助设计系统难以描述异质材料零件(Heterogeneous objects,HEO)的结构信息和材料信息,已有的HEO建模方法也基本上都缺少与通用的建模软件系统及快速成形设备的兼容性。基于此,以几何与材料信息基本映射关系为基础,提出一种基于常用数据格式——表面三角化数据(Stereo lithography,STL)以构建微四面体空间单元的HEO建模方法。通过建立实体、微四面体、STL面片、空间节点四者之间的对应关系,进行HEO实体模型的逐层分解,从而形成被离散化的微四面体空间单元网格节点,并赋予网格节点相应的材料信息,再根据单元网格节点的三维位置及材料值逐一计算各微四面体表面处的结构和材料分布,进而实现整个HEO边界曲面至内部的结构及材料设计,利用实例验证了该方法在复杂HEO设计方面的有效性。 相似文献
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Ying Tie Ruyu Ma Ming Ye Dongmei Wang Chengtao Wang 《The International Journal of Advanced Manufacturing Technology》2006,28(3-4):302-306
This paper presents a non-uniform, periodic closed B-spline approximation algorithm for the fabrication of a medical pelvic
model, based on rapid prototyping, and also gives the finite element evaluation of the pelvic model. Rapid prototyping (RP),
when used in fabricating medical prosthesis, has a strict requirement for closeness and impermeability of STL files. Incorrect
data structure in STL files will cause the subsequent slicing process not to proceed. The non-uniform periodic closed B-spline
curve approximation method was applied to processing CT data. The precision and size of STL files was improved to optimize
the RP model of the pelvis. Finally, the model of the pelvis was evaluated with the finite element method. Results suggest
that a high similarity has been achieved in terms of shape, size and biomechanical properties of the pelvic model and the
normal one, which validates our argument that rapid prototyping with non-uniform, periodic closed B-spline algorithm is suitable
for the fabrication of a pelvic model, which will prove to be significant in the design of pelvic prostheses . 相似文献
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为满足CAD软件与快速成形领域的数据交换需要,提出了一种Parasolid数据的STL变换方法。利用Parasolid建模核心的PK-TOPOL-facet()函数将Parasolid模型按STL文件规则进行三角网格化,通过返回的拓扑信息构建三角面片与它的顶点和法向量的拓扑关系,并由此生成了STL文件。应用实例和Solidworks软件诊断表明,采用该方法可以将Parasolid文件变换为STL文件,生成的STL模型中无错误面和缝隙存在。 相似文献
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Direct Slicing from PowerSHAPE Models for Rapid Prototyping 总被引:4,自引:2,他引:2
X. Chen C. Wang X. Ye Y. Xiao S. Huang 《The International Journal of Advanced Manufacturing Technology》2001,17(7):543-547
Rapid prototyping processes produce parts layer by layer directly from CAD models. An efficient method is required to slice
the geometric model of a part into layers. Several slicing methods are introduced in this paper: slicing from STL files; tolerate-errors
slicing; adaptive slicing; direct slicing; adaptive and direct slicing. PowerSHAPE is a powerful package for building models,
and it provided macro language and picture files for its secondary development work. To meet rapid proto-typing slicing demands,
the author proposes a direct slicing approach based on PowerSHAPE models. In this method, lines, arcs and Bezier curves are
used to describe the section contours. This approach can be used in stereolithography, selective laser sintering, fused deposition
modelling, and other rapid prototyping processes, e.g. laminated object manufacturing. It may be the future solution to existing
slicing problems. 相似文献