快速原型及制造

manufacturing, or layered ma整n理u课f件acturing.
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RP vs. Traditional Manufacture (Machining)
Process characteristics Internal Feature characteristics Product Size
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快速原型及制造（Rapid Prototyping and Manufacturing，简称RP&M）：快速原型（Rapid Prototyping，简称RP）、分层制造（layer manufacturing）、3维打印（3D printing）、桌面制造 （desktop manufacturing），以及实体自由形态制造 （solid freeform manufacturing）
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Sample
STL file solid sample.stl created by Wei Feng on 15th OCT. 1994 facet normal -1.000000 0.000000 0.000000 outer loop vertex 140.502634 233.993075 -38.310362 vertex 140.502634 229.424780 -38.359042 vertex 140.502634 242.525774 -27.097848 endloop endfacet facet normal 0.903689 0.004563 0.428166 outerloop vertex 134.521310 273.427873 30.342009 vertex 134.521310 308.505852 30.715799 vertex 140.502634 334.576026 18.369396 endloop endfacet facet normal -0.903689 0.004563 0.428166 outer loop vertex 140.502634 334.576026 18.369396 vertex 140.502634 294.929752 17.946926 vertex 134.521310 273.427873 30.342009 endloop endfacet ... ... endsolid sample.stl
It contains the coordinates of the vertices and the direction of the outward normal of each triangle.
An approximation of the curved surfaces only.
Increase the number of triangles improves the approximation, but at the cost of bigger file size.
S整o理u课rc件e : The Penn State Learning Fact8ory
STL File Format
The shape of the object is defined by a mesh of tiny triangles laid over the surfaces, like the facets of a cut diamond.
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主要方法：
用激光或者其他光束使相应的树脂聚合 用激光束选择性地使固体微粒或粉末固化 用胶合或熔接的方法粘结液体或固体微粒 切削细薄材料并使其层合 熔化并再固化
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Rapid Prototyping
Class of technologies that can automatically construct physical models from CAD data.
Product Strength Production Time
Rapid Prototyping
Additive processes Complicated
Part Volume 0.125 m3 Low
Shorter 整理课件
Machining Processes Subtractive processes Geometrical
A combination of many thin layers, called slices.
Excellent visual aids for communicating ideas.
Design testing
Faster and less expensive
Synonyms: Solid Freeform Fabrication, Computer automated
Large
High
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Rapid Prototyping Process
1. Create a CAD model of the design
Solid Modeling
2. Convert the CAD model to STL format
3. Pre-processing
Size Location Orientation Auxiliary structure
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基本步骤：首先得到要制造物体的各截面数据， 然后逐层地对各个截面进行堆叠，最后把所有的 层合并起来。
不需要进行基本特征的设计和特征识别 不需要去定义一个原始坯型 不需要设定各种的装置或复杂的流程去处理材料 不需要考虑装夹、辅助夹紧、定位等工序 不需要对模具进行设计和制造
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快速成型制造
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12.1 概要
原理：逐层地把合成材料堆叠起来生成原型 ຫໍສະໝຸດ Baidu优点：可以直接利用零件的几何模型一步地把原型制造
出来。整个过程中不需要工序计划，不需要预处理原材 料的特种设备，也不需要在几个加工中心中进行移动和 传输等 不足：它只能针对某种特定的材料，而NC机床则可以加 工绝大多数的工业材料，包括金属