基于STL模型的抽壳方法研究

Hollowing Process for StereoLithography Model

针对快速原型制造(RPM)和熔模铸造中对壳体原型的需求,提出了一种对零件的STL(STere oLithography)模型进行抽壳的新方法,将零件的STL模型的抽壳过程分解为沿Z坐标轴的偏置和切层轮廓区域偏置,并通过对偏置后的切层轮廓所围成的多边形进行布尔运算,得到了切层后零件的壳体STL模型.由于克服了STL模型三维偏置所面临的困难,因此特别适合对具有复杂曲面零件的STL模型进行抽壳.工程实例表明,该方法缩短了原型制作时间,降低了制作成本,具有实用价值和良好的市场前景.

A new hollowing process of an STL model was presented to meet the demands for hollowed prototypes in casting and rapid prototype manufacturing. To overcome the difficulty in directly three-dimensional (3D) offsetting of an STL model, the hollowing operation is divided into the offsetting along the Z-axis and cross-sectional contour offsetting, and it implements the Boolean operations on the polygons made by the offset contours of cross-sectional contours to produce a thin-shell sliced STL model. This hollowing operation is especially suitable to hollow the STL models generated from the parts with free-form surfaces. This method has been verified by practical cases, which have shown that it can obviously reduce prototype's building time and cost, and therefore can be useful in practice.