Connection With SAP2000 and Orthotropic Materials

Hello All,

I am new to Geometry Gym and honestly not too familiar with how it works. I was searching around online and can't seem to find any kind of tutorial on its use in conjunction with SAP. I'm analyzing small frame structures, so if anyone could link me to or even create a small tutorial that might help, that'd be great. I just need to know the general process of going from a small model of lines to a structure to be analyzed with SAP.

Additionally, due to the small nature of what I work with, my primary building material thus far has been wood, and I can't seem to find a way to implement orthotropic materials. Can anyone shed light on this? I know how to do it within SAP itself but it seems like you create the materials within Grasshopper before the output? Is this correct?

Matt

Replies to This Discussion

Permalink Reply by Jon Mirtschin on August 23, 2013 at 10:57pm

Hi Matthew,

For a start, you can filter my blog for examples tagged as relating to SAP2000 (or other topics) using the tag cloud or direct links such as http://geometrygym.blogspot.com/search/label/SAP2000

The components basically act as a grasshopper user interface for the tables or input dialogs as you know them in SAP, you should recognize the inputs.

It doesn't look like I've implemented orthotropic materials yet, I'll try and do so shortly.

Cheers,

Jon

Permalink Reply by Matthew Horner on September 3, 2013 at 8:21am

Hi Jon,

Thanks, that would be awesome, I'd really appreciate it. I'm glad I found this plugin--should help me a ton.

Best,

Matt

Permalink Reply by Jon Mirtschin on September 5, 2013 at 1:49pm

Hi Matt,

I have coded this to generate the ortho materials but I'm getting a strange run time error. I've contacted CSI tech support, will see what they can advise.

Cheers,

Jon

Permalink Reply by Matthew Horner on September 3, 2013 at 1:44pm

Jon,

I'm having some issues with some of the components here. For example, I took a look at your blog linked here and navigated to the 15 October 2010 date. I downloaded the linked 3 pin truss grasshopper and rhino files and tried messing with them to get a feel of the components. Now, in that file, the component ssiBeam is used, which I'm assuming is likened to the current version's ggSAPFrame? Now, in the old file, I went and created a section property with the new gg component and used it for the truss you had in there with no problems, but when I try to do the same thing for a file of mine that uses the ggSAPFrame component, the sections don't "extrude" right (for lack of a better way of putting it), and the section properties do not get baked into SAP when I use the ggSAPBake component (the element centerlines bake fine). Am i missing something here? Does the baking perhaps fail or go haywire if I don't have supports, or all elements of the structure baking at once (I started with just a few to try to get a feel for it). Any light you could shed on this would be great, thanks for all the help so far.

Matt

Permalink Reply by Jon Mirtschin on September 5, 2013 at 1:51pm

Hi Matt,

Can you post (or email) me the file that doesn't work and I'll take a look. Older versions of files had section properties created in Rhino (I hadn't developed those GH components at the time). Baking elements shouldn't be dependent on having restraints etc.

Cheers,

Jon

Permalink Reply by Matthew Horner on September 7, 2013 at 9:33pm

John,

Attached are the rhino and grasshopper files. Since my last update, I have at least gotten the sections to extrude along the centerlines to which they were intended by changing up a little bit about how they were defined (before, they were somehow just off in space). However, problem number 1 is that they are not solid rectangles, as the plugged-in profile surface would ideally make, but hollow rectangular sections. Problem 2 is that for some reason they are significantly smaller than they should be...take a look at the intended size and you'll see what I mean. Finally, the other problem is as before. The centerlines bake fine into SAP but nothing shows up within SAP under "define section properties." When I used this same ggSAPcreatesectionproperties component with the old file of yours i discussed, where a lot of the components have ssi beginnings, the old file worked fine and imported the section (I made sure "section properties" was checked within the bake component each time). I even tried using the old frame components (called something with "beam" in the title) in my new file and that didn't work. Supports work fine in each case. So I think its just a problem with either my rhino file or the new bake component, but I could definitely use a second, more experienced eye. Thanks for all your help already.

Matt

Attachments:

Problem Rhino File.3dm, 86 KB
SAP Importer.gh, 25 KB

Permalink Reply by Jon Mirtschin on September 8, 2013 at 3:25am

Hi Matt,

I should tighten this up a little for the SAP plugin. Some of the other analysis software can accept a generic curve or surface to define a cross section property (for example, http://geometrygym.blogspot.com/2011/11/nurbs-to-structural-analysi... ) but with SAP I believe it's limited to standard shapes.

There are some components for standard shapes in BullAnt, refer the attached file and let me know if it doesn't work better (or make sense).

Cheers,

Jon

Attachments:

SAPImporter.gh, 24 KB

Permalink Reply by Matthew Horner on September 8, 2013 at 7:31am

Jon,

This works very nicely, thank you so much! The reason I am so intent on solid sections and orthotropic materials is because the structure is made out of wood, and is actually already built; a lot of what I'm doing is improving my methodology for future models and prototypes. Within SAP, the way I obtained such a section before was to use its built-in "section designer" (when you select "other" in the frame section property type menu when defining a new section property). There you can draw a solid rectangle used to approximate your section. So, I don't know if its possible to allow, say, rectangular surfaces to be used as section profiles in geometry gym and then have them feed into SAP via this section designer (if that's even how it works) or not, but at least we know the sections are possible in SAP. If its not possible, particularly difficult, or even just not high on the priority list right now (you clearly help a lot of people with a variety of things), that's totally fine; it wouldn't be the end of the world if I even had to define the section each time within SAP itself, that part is very quick at least. But let me know what you think, you've been so much help already, and thanks for the recent file!

Best,

Matt

Permalink Reply by Matthew Horner on September 9, 2013 at 9:09am

Jon,

One additional thing...have you had any issues in the past with Grasshopper files not working for anything other than their original corresponding Rhino files? I tried the same code you sent me with another Rhino file with the same structural shape and centerlines, and it didn't work...but then I re-downloaded what you sent and put in the exact same dimensions and it worked. Any thoughts?

Best,

Matt

Permalink Reply by Jon Mirtschin on September 9, 2013 at 9:22am

No, unless explicit reference to rhino model objects are in the gh def, it should be immune to the rhino document open. The only exception is scale. My plugin checks the rhino document units (metres, feet, inches) and scales the magnitude of grasshopper lengths accordingly.

If you post or email some files for me to test, I'm glad to advise further if you can repeat the problem.

Permalink Reply by Matthew Horner on September 9, 2013 at 9:35am

Nevermind, I just figured out how to fix it, although I don't really know why it has to happen this way but whatever haha. It turns out that if I open the Grasshopper file before the Rhino, it doesn't work. But the other way, its fine. So if I wanted to shift between Rhino files, I would just have to close the Grasshopper program before opening a new one. Works for me, thanks! Let me know if you have any additional thought any time soon on the solid rectangular sections. One thing I'm trying is just making the RHS section thickness enough to make it solid, which at the very least works visually, but I'd still have to check as far as structural analysis goes. Thanks!

Matt

Permalink Reply by Jon Mirtschin on September 9, 2013 at 10:09am

Does your default template have the same units (feet) as you document? If you recompute the gh definition does it work (if you started gh before document)? Can you share your initial template and I can test here?

I think the analysis plugins still do an accurate preview (including wall thickness), for some of my plugins (IFC) I am working on options for fast preview or detailed (to keep it fast for large models). I don't recommend setting wall thickness to large values to fudge it, I don't check for this and I'm not sure that SAP will like it.