how to read mesh properties from cad using an external program

[kr276]

Hi, I am to write a code in FORTRAN which can calculate the section properties of any arbitary shape. The idea is to draw the section in autocad and then mesh it with user defined option (square meshes of unit size). my program is supposed to read the cad file and get the section properties (ie; Area, section modulus etc). i know that cad has option region>massprop> to get this, but i dont have full option cad, hence looking to develop this program. i wish to know if any one has good ideas on this. is it possible to read the coordinates of mesh from autocad file (if saved in a different format)

 

[MikeHalloran]

The AutoCAD .DXF file format is publicly documented, and is already accepted as a lingua franca for communicating geometry among many CAD and CAM programs, so I'd likely start with that, if it's allowed in your problem statement.

From there, I might use recursion, i.e., write a routine to calculate the section properties of a given region using squares of arbitrary size, then call the routine using smaller squares, and keep calling the routine with smaller and smaller squares until the properties stop changing, or change by less than some defined threshold of precision, or you just get tired of waiting for the computations to complete as the number of squares increases.

Real mesh generators are smart enough to only use small squares where the geometry demands it, but uniform squares should do for a start.





Mike Halloran
Pembroke Pines, FL, USA