AutoCAD to FLAC3D模型转换方法

针对FLAC^3D前处理功能较弱的特点，提出了一种AutoCAD to FLAC^3D模型转换方法，将建模工作转移到建模能力较强的AutoCAD软件中。该方法的核心思想是将AutoCAD模型分解成长方体单元，将单元数据导入FLAC^3D中。其实现过程：在AutoCAD中设定模型分组，指定最小单元尺寸限定尺寸，将模型进行分区，区间模型各组间进行布尔运算；然后以区间尺寸大小的长方体与区间模型进行布尔运算，如果运算结果是长方体且只有1块，则结束计算并保存；如果不是，则将区间分解为8个子区间，每个子区间与区间模型再进行计算，直至区间尺寸小于最小单元限定值为止；随后提取分解形成的长方体形3dsolid对象顶点坐标值，汇总各区间分解单元、坐标存入汇总文件，提取坐标、单元及其分组等数据写入后缀为.FLAC^3D的文件中，由FLAC3D导入网格命令读取文件，完成模型转换。应用该方法可以在不简化的前提下建立复杂模型，提高模拟相似度，降低建模难度，提升建模效率，实现快速、精准建模。

Model Transformation Method from AutoCAD to FLAC3D

As the pre-processing function of FLAC3D is weak,a method of model transformation from AutoCAD to FLAC3D is put forward,the modeling process will be transferred to AutoCAD with stronger capacity in modeling. The core idea of this method is to disintegrate AutoCAD model into rectangular units and to import unit data into FLAC3D . Implementation procedure is as the following:To set up model grouping in AutoCAD and the minimum unit limited sizes,the Boolean operation is done a-mong various groups of interval models. After that,the Boolean operation is done between rectangular units of interval dimen-sion and interval models. If the results of Boolean operation is rectangular and has only one piece,then calculation can be en-ded and saved. If not,then the interval will be disintegrated into eight sub-intervals and models of every interval will be re-cal-culated until the dimension of interval is smaller than the minimum unit limited sizes. The next step is to extract 3dsolid object vertex coordinates in rectangular form from the disintegration. Disintegration units and coordinates of various intervals will be collected and saved to summary file. Data like coordinates,units and subgroups will be written on the file with suffix . FLAC3D . In the end,FLAC3D will lead in grid by 'import grid' command and the whole process of model transformation is completed. This method is good to design complex models on the basis of non-simplification,improve simulation similarity,lower modeling diffi-culty,enhance modeling efficiency and further make modeling to be fast and accurate.