激光直接制造和再制造中的三维CAD模型直接分层技术

在分析SolidWorks软件平台下CAD模型数据的内部表达方法以及拓扑信息和几何信息提取方法的基础上,研究三维CAD模型直接分层技术.对SolidWorks进行二次开发,调用SolidWorks应用程序接口函数中的曲面一曲面求交函数对CAD模型曲面与分层平面求交,得到的交线首尾相连形成轮廓轨迹;同时研究了光栅填充扫描算法及程序实现.为实现切片数据的通用化,设计了记录切片数据的文件格式,用直线、圆弧或圆描述分层轮廓.对上述的直接分层不仅进行了软件模拟,还用于直接制造.制作的试件与STL间接分层试件比较结果表明,采用直接分层的试件的精度和表面质量优于STL间接分层.

Direct Slicing of 3D CAD Models for Laser Direct Manufacturing and Re-manufacturing

A direct slicing approach from 3D CAD models is proposed by studying the data structure of SolidWorks solid models and the method of obtaining geometric and topological information from SolidWorks CAD models.Based on SolidWorks platform,a direct slicing program has been developed,in which surface-surface intersection function of application programming interface(API) is called to get the section contours.Tool path is generated by sorting the section contours end to end.Raster filling algorithm is studied and implemented to compute the tool path for filling.The slices data are saved in a special file in which lines,arcs and circles are used to describe the section contours.The file is independent of SolidWorks.The direct slicing result is simulated.Part fabricated with application of the direct slicing software is compared with that based on stereolithography(STL) format.It is shown that the accuracy and surface finish of the direct slicing part is better than that of STL indirect slicing.