【作者】 彭蓓；

【导师】 任继文；

【作者基本信息】 华东交通大学 ， 机械制造及其自动化， 2009， 硕士

【摘要】 选择性激光烧结(Selective Laser Sintering,SLS)是20世纪80年代末出现的一种快速成型工艺,它利用计算机控制激光束对粉末薄层以一定的速度和能量密度按照分层面的二维数据进行扫描烧结,层层堆积,最后形成成形件。其工艺涉及机械、材料、粉末烧结、激光加工等相关学科。本文以SLS加工工艺作为研究对象,开发了SLS加工仿真系统平台,该平台能够对SLS加工过程进行几何仿真,同时对仿真系统的实现过程中的各种关键技术进行了研究,主要研究内容如下。利用Visual C++和OpenGL完成了仿真场景的构建及仿真界面的设计。在构建仿真环境时根据加工仿真环境的需要,采用合理的光照模型和材质,增强了加工仿真的真实感。基于开发功能要求,实现了统一界面上多窗口的三维图形显示与同步控制。使用Pro/E的二次开发工具Pro/TOOLKIT编程实现了基于Pro/E的直接切片算法。该算法避免了模型转换为STL文件时所造成的切片误差,能够安全、高效、精确的获取3D CAD模型的切片轮廓数据。同时采取了自定义MSlice文本格式和基于OpenGL的图形方式来实现切片数据的存储和显示。对各种类型的扫描路径方式进行了分析,实现了S形扫描路径曲线对切片轮廓的填充。实现了SLS加工设备的三维静态建模及SLS加工动态仿真。根据计算机图形的反走样、混合和图形消隐等图形处理技术,利用OpenGL和Pro/E完成了SLS设备的三维静态模型;在分析SLS加工过程中的各机构运动关系的基础上,由S形路径曲线填充切片轮廓后得到的节点坐标编程实现了激光扫描路径的运动控制。最后运用OpenGL的双缓存技术以及Windows自带的定时器实现SLS加工过程的实时动态仿真。本仿真平台具有良好的交互性、实时性和可移植性。不仅节省了资源,还可用于理论研究成果验证和教学演示,对SLS工艺的研究具有重要的理论和现实意义。更多还原

【Abstract】 Selective Laser Sintering (SLS for short) is a Rapid Prototyping technology invented in the 1980s, which uses computer-controlled laser beam scanning thin-layer and sintering power with a certain speed and energy density according to sub-lever two-dimensional date, accumulating layers, resulting eventually in forming part. Its process involves machinery, materials, powder sintering, laser processing and other related disciplines. This thesis was based on SLS process, developed a machining simulation system platform. This platform could realize the SLS geometric simulation of maching process. The key technology related during the realization process of simulation platform was researched.An interactive 3D simulation environment was built up using Visual C++ and OpenGL. In building a simulation environment, the reality of the simulation process was enhanced by using reasonable illumination model and material. Based on the development of functional requirements, the system achieves 3D graphics’display and synchronization control in a unified multi-window interface.Through the secondary development tool Pro/TOOLKIT, the direct slicing algorithm was achieved. This algorithm proved to be safe, efficient and accurate as avoiding the slice error which was caused by converting the part model to STL file. The slice data was stored by a self-defining text file and displayed by OpenGL graphics.The various scan method was analysized and compared. The function of filling an arbitrary profile with S-shaped scan curves was realized.The 3D static modeling of SLS equipment and dynamic simulation of SLS machining process were implemented. Base on the graphics processing technology of computer graphics such as anti-aliasing, blending and graphics hiding etc., the three-dimensiona static modeling of the SLS equipment was constructed by Pro/E and OpenGL. On the base of analysizing using OpenGL animation technology, the real-time dynamic simulation of SLS machining process was realized by controlling the laser scan in the slice contour of 3D model.This platform possesses a good interaction, real-time performance and portability. Not only can it save resources, but also can be used to verify results of theoretical research and teaching demonstration. It has important theoretical and practical significance for the research of SLS process.更多还原