面向快速成形的异质材料零件三维CAD表达方法与系统
文献类型：学位论文
| 作者 | 吴晓军 |
| 学位类别 | 博士 |
| 答辩日期 | 2004-06-23 |
| 授予单位 | 中国科学院沈阳自动化研究所 |
| 授予地点 | 中国科学院沈阳自动化研究所 |
| 导师 | 王天然 ; 刘伟军 |
| 关键词 | 快速成形 异质材料零件 体素化 科学计算可视化 异质材料CAD系统 |
| 其他题名 | Rapid Prototyping Oriented 3D CAD Representation Approaches and System for Heterogeneous Material Part |
| 学位专业 | 机械电子工程 |
| 中文摘要 | 本文提出了一条从CAD网格模型到适合快速成形设备使用的带有材料信息二维层片接口文件输出的数据流程，为基于RP的异质材料零件制造提供技术基础。主要工作总结如下： 1.将零件的多材料模型、功能梯度模型和嵌入器件零件模型统一定义为异质材料零件(Heterogeneous Material Part，HMP)； 2.提出了基于Loop模式的自适应曲面细分算法，提高模型曲面部分的精度同时保持了模型上的尖锐特征不被磨光； 3.实现了基于图像空间的深度缓存快速体素化算法，提出了基于物体空间的八叉树结构和基于最小欧氏距离测度的CAD网格模型体素化方法； 4.重新定义了基于距离场的HMP表达方法，改进了该方法不能对负材料均匀分布区进行材料赋值的缺陷。提出了固定参考特征&活动梯度源(Fixed reference feature(s)& Active grading source(s)，FRF&AGS)的概念，提出一种基于FRF&AGS的HMP表达方法，避免了重新计算模型内点到新AGS的距离； 5.提出了一种基于零件几何切片轮廓约束的三维层间和二维层内材料信息重构算法，解决了低分辨率体素模型的材料切片与几何切片轮廓精度的一致性问题； 6.提出了适合HMP体数据场的直接体绘制流程，实验证明了所述方法的可行性并具有很好的绘制效果； 7.研制开发了国内第一套具有自主知识产权的三维模型异质材料表达及带有材料信息二维切片输出功能的CAD系统。 |
| 索取号 | TH166/W85/2004 |
| 英文摘要 | A representation framework and a data pipeline from CAD mesh model to 2D slicing with heterogeneous material information for RP machine are proposed and implemented, which makes it possible to manufacture HMP by RP technology. The main contributions are summarized as follows. 1.MMO, FGM and OEC are defined as heterogeneous material part, short for HMP. 2.An adaptive subdivision surfaces algorithm is proposed based on the Loop scheme to improve the smoothness of the curve surface while maintaining the sharp features of a model. 3.Z-buffer (ZB) based fast voxelization in image space is implemented. Two voxelization methods are proposed based on octree structure and minimal Euclidean distance (MED) respectively. 4.By the definition of distance field (DF), a HMP modeling algorithm on the basis of DF is presented, which overcomes the drawback of being incapable of evaluating material in negative constant material area. The conception of fixed reference feature(s) & active grading source(s) (FRF&AGS) is proposed. Based on FRF&AGS, a new HMP representation framework is developed, which is effective and flexible for avoiding the DF recalculation from object voxels to AGS when the AGS is changing. 5.A material resample algorithm between neighbor material slices and in a single slice is proposed based on the geometric slicing constraints, which can compensate the precision loss of voxelization while improve the resolution of HMP slices to approximate the geometric contour shape. 6.A direct volume rendering (DVR) pipeline for HMP datasets is proposed. Experiments show that the image quality is high and it is necessary to visualize the HMP volume dataset. 7.A heterogeneous material CAD modeling system is developed, which is the first prototype system in domestic. It can not only offer a powerful data pre-process tool for RP machine to produce HMP but also establish a good foundation for carrying out the research of RP based HMP manufacturing. |
| 语种 | 中文 |
| 公开日期 | 2012-08-29 |
| 产权排序 | 1 |
| 分类号 | TH166 |
| 源URL | [http://ir.sia.ac.cn/handle/173321/9562]  |
| 专题 | 沈阳自动化研究所_工业信息学研究室_先进制造技术研究室 |
| 推荐引用方式 GB/T 7714 | 吴晓军. 面向快速成形的异质材料零件三维CAD表达方法与系统[D]. 中国科学院沈阳自动化研究所. 中国科学院沈阳自动化研究所. 2004. |
入库方式： OAI收割
来源：沈阳自动化研究所
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