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Risa to offer non linear static and time history analyses?

Risa to offer non linear static and time history analyses?

Risa to offer non linear static and time history analyses?


From your days at Risa, was there a goal to offer non linear static and time history analyses?

The static option would be more valuable for me right now. I think they would start by allowing plastic hinges to form. Then start incorporating material hysteresis behavior to allow time history analyses.


RE: Risa to offer non linear static and time history analyses?

Cody -

Well, you can't take anything I say as gospel anymore. I'm not on the inside. Even when I was still employed by RISA, I was kept in the dark about long term planning for the last year or so I was there. You might ask their tech support to see what they think. They may know more now than I do. :)

That being said, it would be a shock to me if they did anything major with non-linear anytime soon. They've got developers who could do the programming for sure. What they don't have is actual engineers with non-linear analysis experience. At least, not to my knowledge. And, you really want someone like that to map out the project so that it'll work the right way for the actual engineers who end up using it.

Since this is a relatively broad topic, my thoughts would be broken down more specifically:

1) Geometric Non-linearity - Geometric stiffness adjustment for doing P-Delta/p-little delta: I wrote some pretty good and detailed specifications over the years on how to do this (not just technically, which the developers could handle) but from an interface standpoint. So, this could be done fairly easily.

My guess, however, is that without me there to champion it (or Mike Olson who was also very interested in the topic) there isn't anyone really excited about this feature and ready to push for from the technical standpoint. Therefore, it probably becomes a sales / marketing decision. If enough users request it, or management thinks they can gain a competitive advantage (over RAM, for instance) by doing it, then it will happen. If not then it will be a while before it happens.

2) Geometric Non-linearity - Cable elements: I don't think this is going to happen anytime soon. I don't believe I ever wrote a spec for this, neither did Roger. Obviously, someone else could write the spec. But, unless they hire an Engineer with a lot of experience in cable structures, it would take a good amount of time to get a proper grasp on it. So, even if they decided to do it today, it would be a couple of years before they could get it done properly.

3) Material Non-linearity - Static: I don't really see this happening for RISA anytime soon. Maybe some day in the distant future. But, the amount of development work required compared to the small number of engineers that actually request it make it unlikely. That may not always be the case. I guess it becomes a question of who they're competing against. Do they want to catch up to SAP 2K - nonlinear? Or, do they want to continue to match / beat RAM and STAAD? My guess is that they are perfectly happy conceding the high end analysis to the SAP guys, as long as they continue to beat RAM and STAAD. Maybe if S-frame, Robot and / or Visual start beating them in their analysis, and pulling away market share then they'll be interested. But, until then I have my doubts.

4) Material Non-linearity - Dynamic: This isn't even a pipe dream right now. Certainly not until the static non-linear is done.

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