RISA-3D Alternate Post-Processor?

[nwedding]

Does anybody know of a way to use an alternate post-processor to display plate results from RISA-3D? I can print a flat file of the input and output, but it seems to be in a risa-only format - not one that's recognized by something like paraview. I have a wide range of forces and stresses to display, so the contours from the internal generator are displaying results that are very misleading, even when I try to change the minimum and maximum range.

 

[JoshPlumSE]

Nope.... RISA doesn't have anything like that. The closest you will get is the spreadsheet results which can be imported into Excel (or any other spreadsheet program).

I've used Excel in the past to combine My and My with Mxy moments to come up with a better representation of the demand moment for reinforcement design. Though nowadays, that's probably more easily done using RISA's internal force summation tool.

 

[nwedding]

Hi Josh. Thanks for answering. I've got a plate model of a concrete shaft with a hole in the side and uneven external pressure. The contour plots are wacky compared to the results spreadsheets. I was hoping to feed the spreadsheet info to one of the open-source visualization packages with more control over the contours.

I haven't used the internal force summation tool before. Are the moments and forces that come from the tool good for design without further manipulation?

It's funny that you saw my question and answered - I actually wanted to ask you about this, but I thought you might not appreciate folks tracking you down to ask RISA questions

 

[JoshPlumSE]

Did you try contacting RISA technical support first? Just curious because they should have been knowledgeable enough to point you in the right direction. At least, unless something major has changed since I left.

The model you describe is one where it sounds like you could have issues with the plate local axes not being consistent. That's very common. Now, the problem with this is that the contour plots interpolate between adjacent plates. So, if you're plotting the local y moments then the local y moment for one plate can mean something completely different than the plates next to it. Therefore, this can really mess up the plate contours in any region where plate axes don't line up nicely. Ugh!

The plate force results spreadsheet doesn't get messed up because they are reported for an individual plate and not affected by orientation of any adjacent plates.

There are a number of ways to work around this contouring issue. The ones I would recommend are the following:
1) In the most recent version of the program there is a setting on the (Global) Model Settings - Solution tab for aligning your plates to the GLOBAL axes instead of the default local / nodal axes of the plate. Now, I wasn't involved in creating this feature. But, if it works correctly, then it should solve your problem.

2) The internal force summation tool. Just select only the elements for which you are interested in getting a moment. Then use this internal force tool to cut a plane through these elements. The tool will report the internal forces and moments relative to the cutting plane and line that you created. Therefore, it converts all the goofy local plate forces into the forces in the orientation you are interested in. This tool is GREAT for shear walls or structural slabs or such. It may not work quite as well for your case (cylinder) because it's tougher to get the orientation of your cutting plane just right.

 

[nwedding]

I did call RISA support first, but they weren't able to help much with this particular issue. I think my results are just difficult to plot with the limitations of the current contouring engine/smoothing algorithm. My plate local axes are consistent in this model. I paid close attention to them when setting it up, but I didn't have to do much since the plate local axes was set to global, and it worked great.

The internal force summation tool is nice - I'll have to experiment with it some to understand which direction the forces and moments are being given. With the plate forces, Fx is hoop force for me and Mx is the moment in the hoop direction (not the moment around the x axis). In the ifst, is F1 the force in the 1 direction and M1 the moment acting on the 1 cross-section or the moment about the 1 axis?