AutoCAD- Need help to draw a corroded rectangular plate in a script file

[xxpochita123]

See attached file for the example. It doesn't belong to me so I don't know how it was made.

I need to draw a corroded rectangular plate. The depth of corrosion is given using x,y,z coordinate points. I can't use extrude or loft because the surface is non-planar. Also, this is a repetitive process so I need to do this by script. One model consist of tens of thousands of blocks, and I still have more than 30 models to go.

I tried 3D FACE > CONVTOMESH > SURFSCULPT but the meshing is wrong. Which is why I want to draw it per 1x1x7.1mm blocks (1x1mm is the cross section and 7.1mm is the thickness or height of the block). 

Is there a way where I can make a 3D Solid (using script, since I don't know how to write a lisp or VBA, and studying them would cost me some valuable time) with uneven surface (it's a corroded rectangular plate, which is why it's uneven) without having to use the CONVTOMESH command? I'm open to other suggestions (e.g. using a different software) as long as I could produce this drawing.

***THE POST TITLE HAS BEEN EDITED FOR CLARITY***

[ The subject line of this post has been edited to include the product name by @handjonathan ]

[Kent1Cooper]

[Did you post the right drawing?  It's very planar, and I don't see anything I can interpret as representing corrosion.]

[xxpochita123]

Yes, it's the right drawing. The corrosion surface is too smooth which is why it's not that visible, but you can see the waves if you look at the right view.

[pendean]

Forgive me, but the posted file is just a large number of 2DLINE entities, not much else

[xxpochita123]

Kimdly check this file.

[Kent1Cooper]

[Never mind -- written before the new A3 drawing]

[leeminardi]

I assume you created a bunch of 3D Faces from the point data.  How did you do that?  Are you satisfied that the faces capture the detail you want for the "uneven surface".  

There are a variety of ways to construct an uneven surface in AutoCAD.  Two popular methods are via LOFT and SURFNETWORK.  Once you have a surface you can create a solid via SURFSCULPT.  What formats for data does Abaqus accept for FEA?  Will it accept NURBS surfaces?

Can you post a sample of the data that you are working with?

[xxpochita123]

Here are the coordinates in CSV file.

The attached DWG file in this post entitled 'A3' is not my doing. Somebody else had done it, but he's no longer in our laboratory so I can't ask him. I want to know how that kind of drawing was done in AutoCAD by simply running a script.

What I actually did was create a bunch of 3D Faces (3DFACE), convert them to mesh (CONVTOMESH), and then convert them to one whole solid object (SURFSCULPT). Obviously, this is not how it was done in the uploaded file. If it's possible, I don't want to mesh it in AutoCAD (as I plan to mesh it in Abaqus). I just meshed it because I can't think of other ways to make a 3D Solid object with uneven surface. Also, this method takes soooo much time (maybe more than 3 hours to convert it to 3D Solid).

Anyway, after creating the corroded rectangular plate, I need to roll it to make it into a cylinder with circular cross section. I don't think this can be done in AutoCAD. I was able to do this in 3DS Max (using the 'Bend' feature). After that, I'll export it as SAT file and import it to Abaqus.

[leeminardi]

As a proof of concept I used Excel to create polylines in AutoCAD for the first six profiles (the profiles with Y values of 0 through 5).   Since the planes of profiles have constant Y value we want to enter x,z data with the elevation used to define the plane.

The Excel concatenate command was used to create comma delimited values for x and y from the x and z values of your data.

The elevation was first set to a value of -Y (minus Y) followed by the pasting of the x,y (actually x,z) values for the polyline.  The elevation was then set to the next -Y value and the data for that polyline pasted into the pline command.  The process was repeated until there were 6 profiles.   Rotate3d, all   about 0,0,0 (WCS) by -90° yields contours in planes parallel to the XZ plane.  The profiles are colored below to help in visualizing the data.

The loft command was then used to create a surface.  Here 's the surface with one isoline in u and v.

Five flat planes were then created and positioned to define a bottom and four side to define a watertight volume.

Surfsculpt is then used to create a solid referencing the six surfaces.

Since there are over 500 vertices for each profile I would consider creating solids for groups of profiles (e.g., 6 to 10) and then union the resulting solids into one solid if necessary.

What type of FEA elements do you plan to use in the analysis.

If you want to model a cylindrical object from the data you could use rotate3d to position the profiles about a central axis and then use loft.

[xxpochita123]

Thanks a lot for this. I'm lost after the Rotate3D part. How is it going to form a cylinder?

[leeminardi]

To create a cylindrical shape object move the profiles in z to establish an effective radius. Use rotate3d to rotate each profile about its new axis by an appropriate angle.  Since you have 60 profiles this would be 6°.  Use loft and surfsculpt to create a solid rod.  The following shows 6 profiles repositioned and rotated.

Since each profile has so many vertices I might consider subdividing the profile into smaller section.  E.g., perhaps a 100 vertices each.

[xxpochita123]

Is this possible via script? Because in 3D Rotate and Loft, I think you need to select the object, which I don't think is possible (or at least I don't know how to do in) script.

[leeminardi]

Script, maybe.  VLISP yes.  THe program could select each profile via a selection point which can be calculated from, for example, the first vertex's coordinates and  how its been rotated.   Being able to select the profiles in order would only be necessasry for the loft command. The creation of the profile and then its rotation with rotate3d (not 3drotate) could be done with select last.

[xxpochita123]

leeminardi's way of drawing the corroded plate is easy, but I want it to be drawn like this...

The model consists of multiple 3D Solids with uneven surfaces.

[leeminardi]

By "like this" do you mean you wan to create a solid?  The loft command will create a solid if the sections are closed.  If you don't get a solid from loft you can use surfsculpt afterwards to convert a surface model into a solid.

[xxpochita123]

I want it to be drawn like this one, wherein the mesh was drawn one by one so that they will be of equal sizes

[leeminardi]

@xxpochita123 you state "I want it to be drawn like this one, wherein the mesh was drawn one by one so that they will be of equal sizes".  Why? In your post #8 you state that you will create the finite element mesh in Abaqus.   I think Abaqus meshing would work better referencing a single solid than an array of many solids. It's not clear

You state "after creating the corroded rectangular plate, I need to roll it to make it into a cylinder with circular cross section. "  At what stage and with what software will this rolling be done or will you be doing the FEA on the "rolled" (cylindrical) solid and the plate.

You never answered my question in post #9 "What type of FEA elements do you plan to use in the analysis?"

Do you have much experience with  FEA in general and Abaqus specifically?

It's difficult to provide good advice when the task you are trying to do is fed piecemeal.

[xxpochita123]

I tried to mesh it in abaqus using both hexahedral and tetrahedral element types, but I received poor mesh results. I'm also not a professional in using Abaqus, so I still have to ask my colleagues to check my Abaqus model. Also, I used Inventor to roll the plate to make it into a cylinder.

Here's a sample on what the mesh looks like if I use tetrahedral.

[leeminardi]

I'm sorry but I think I have provided as much help as I can.  I will have to bow out from this discussion.

Good luck.