机械工程英语第2版part2第11单元翻译.docx

Unit11 Rapid Prototyping and Manufacturing Technologies 快速成型与制造技术Introduction 导言Manufacturing community is facing two important challenging tasks: Substantial reducition of product development time; and Improvement on flexibility for manufacturing multi-variety and small batch-size products. Computer-aided design and manufacturing(CAD and CAM) have significantly improved the traditional production design and manufacturing. However, there are a number of obstacles in true integration of computer-aided design with computer-aided manufacturing for rapid development of new prodcts.制造社会面临两个重要的富有挑战性的任务：大幅度减少产品开发时间，提高多种产品，小批量大小产品的制造灵活性。计算机辅助设计与制造(CAD 和 CAM)有着显著改善了传统的产品设计及制造。然而，在新产品快速开发方面有一些障碍，这些障碍阻碍着计算机辅助设计与计算机辅助制造的真正集成。To substantially shorten the time for developing patterns, moulds, and prototypes, some manufacturing enterprise have started to use rapid prototyping(RP) methods for complex partterns making and component prototyping. Over the past few years, a variety of new rapid manufacturing technologies, generally called Rapid Prototyping and Manufacturing(RP M) have emerged; the technologies developed include stereo lithography(SL),selective laser sintering(SLS), fused deposition modeling(FDM), laminated object manufacturing(LOM), and three dimensional printing(3D Printing). These technologies are capable of directly generating physical objects from CAD databases. They have a common important feature: the prototype part is produced by adding materials rather than removing materials, that is , a part is first modeled by a geometric modeler such as a solid modeler, and then is mathematically sectioned(sliced) into a series of parallel cross-section pieces. For each piece, the curing or binding paths are generated. These curing or binding paths are directly used to instruct the machine for producing the part by solidifying or binding a line of material. After a layer is built, a new layer is built on the previous one in the same way. Thus, the model is built layer