Problems re-importing an analytical model

[david_peterson]

That seems to be part of the "It dose everything" "Problem" with Revit. While I love the concept, and it may not take long to find limits of 1 3rd party app, I haven't heard any one of my engineers say they only use 1 app.

We use Ram, Safe, E-tabs, Risa, and a few others. Our engineers like to use different apps for different systems in the building.

Here's yet another question. When RS says it works with Risa, is it just Risa 3d or will it work with Risa floor? Will it work with Ram, or the whole suite of Ram products.

The more I play with it, the more I wonder about the limitations of the product and how I may have been suckered in to the RS world by a Sales pitch. I want to see this product work (mainly because we've already paid for it) but I'm thinking that we will still have to check the 3rd party model against the RS model, which goes against the whole concept. Which brings me to my next point.

What happens if you get a hick-up with RS and you re-import the model, the member sizes don't change, you send out the drawings with wrong sizes on it because you took the "link" at it's word. When you realize it, the shops have been approved and now you have to eat the steel, or worse yet, it gets put up, constructed, commissioned, and collapses a year later. Dose Adesk pick up the tab? I didn't think so. At least in the 2d world you knew you had to check everything twice against the model. This kind of leaves me with a false sense of security. Sorry to go off on a rant, but I feel like what we bought and what we were sold are 2 different programs, and we got the wrong one.

[Tom Weir]

Hi,

We use Ram, Safe, E-tabs, Risa, and a few others. Our engineers like to use different apps for different systems in the building

But still the idea that you would only make one model in RS for use in all of those other programs, rather than re-building the model for each app. would seem to have genuine appeal for the engineer.

We need to keep seeing more apps. get on-board...

As for the validity of the re-imported data, hopefully experience spanning many projects will start with lots of checking at first, until one is satisfied that the integrity of the data is maintained during the import\export process.

Tom Weir
Los Angeles

[kmarsh]

To answer some of your questions David;
Risa3d (as far as I know) only offers a link to Risa3d but is working on a RisaFloor link. Here is Risa3d's statement about what features the link currently supports: http://www.risatech.com/partner/down...uctureLink.pdf
Take a minute to read through that, it should answer some questions about what features are supported and which way (direction). For instance, it does indicate that only member size changes are mapped back into RS (as shown by experiment).

Basically (as I understand it) each 3rd party developer is responsible for making use of the information exposed by Revit Structure through the API (application program interface). This is information pertaining to grid locations, member locations and sizes, and other RS model information like loads etc. The 3rd party developers now have to take that information and programmatically create the analytical model in their software. The 3rd party can then send back a certain amount of information (this may be limited by the 3rd party functionality OR by the amount of information exposed for modification through the API by the Revit folks.) Additionally, Revit API provides a method for 3rd party developers to supply additional information about each member (enveloped end moments or max reactions etc). This is another area where each 3rd party is on their own to supply as much or as little information as they see fit. I do know that Revit is encouraging 3rd party development in this area of unique information returned from analysis to RS so I would expect to see this blossom in time.

You mentioned the apparent "need" to check the analytical model against the revit model: Like Tom said, this is probably a good idea anyway for a while, until a level of personal confidence is reached. To some degree, if you can get your engineers to start working with RS by showing them that it is not a "drafting" package but a BIM package, they really can do most or all of their analytical modeling with RS. There are obviously some features (moving loads, or spectral response loading, maybe others?) that are unique to an analysis package and need to be added in the 3rd party software. However, you wouldn't expect to have that info come back into RS. It really is a paradigm shift for both drafters/designers and engineers: to make full use of RS, we must progress toward a more flowing interaction between drafters and engineers, because you are both working on the same model.

If your salesman "sold" you that the engineers just keep on doing everything like "business as usual", then yes, you were sold a "bill of goods". The engineers need to evolve (can't believe I have to say this... we engineers are SUPPOSED to be technically savvy, into high-tech, forward thinking... but apparently, on the average, we're not. *hangs head dejectedly* perhaps, more likely, we were just dense enough to not switch to a finance major during any of the 5 calculus classes we suffered through)

So, what i'm getting to is simply that less "work" should be done in the analysis packages and more done in RS. Let the 3rd party stuff do the analysis, analyze the deflected shapes, check the unity's, prepare your analysis reports etc. but do the rest of the stuff (moving stuff around, adding members, loads and changing end releases) in RS, then enjoy the fact that all the sizes came out of your analysis package and updated automatically in RS and all your drawings are coordinated!!!! No more "so, Mr. Engineer, did you want the steel beam size you showed on the plan or on the elevation? Because we priced the smaller one....

Anyway, I'm looking forward to RS, I haven't yet been able to convince my old school purse-string-holders to go for it yet, but i'm working on 'em.

[david_peterson]

I think it'd be great to never need to draw a plan again, and let the EOR make his/her own mistakes and I stick to the detailing. If those darn Architects and MEP people could figure out how much room a W24 beam takes up, I wouldn't need to even think out this.

[Tom Weir]

Hi,
I have been seeing things evolve in my office for two years. At first we just started modeling in the original Revit package (5.1 through 7.0). Of course, there was no analytical link then. The engineers were not very involved in the production of the physical models then. But they started seeing that BIM and modeling could produce a more accurate and coordinated set of construction documents.

But now that RS2 is out and the analytical link has been established I see they are taking more notice. It is a "paradigm shift" in workflow, and in a busy office not an easy thing to do.

On one job I am doing the engineers wanted to use the analytical model to compare to what they had done in SAP and ETABS independantly. Since the Revit analytical model was already there it was easy to accomplish. And I think that will help them feel more comfortable with the process.

On another job with a complicated column layout they had me write the analytical model to an ETABS file, then they exported that model to SAP. It saved them a great deal of time. Word is getting out...

I just bought 2 network floating licenses for the engineers to use so they can now be more involved in the Revit model building process.

I also am starting training sessions for engineers with the idea of concentrating on the integration link issues. I also want them to at least be able to open the Revit model file, zoom and pan, view the 3D model, spin it around. Before long I expect they will want to work in Revit and save their changes. One good example is the graphical column schedule. To update column sizes throughout the project, the engineer can simply open the schedule, highlight the column, change the column size as needed, and bingo... he is done. No mark-ups for the draftsperson, no checking the mark-ups afterwards.

That's how I am trying to involve engineers and segue to the new workflow environment, and trying to break down the old way of ...engineers on this side.....draftspersons on thiat side.....attitude.

Tom Weir
Los Angeles

[kmarsh]

The really fun part (to me) is just that: the way RS allows worksets, you can break up the work-flow any way you like. You manage the plans as much or as little as you collectively decide and break up the worksets thusly.

For instance, (as i understand it) you could manage the member locations etc. and the engineers can have the loadings and member end releases to play with (in which case, they still get to make their own mistakes like before) or you could actually let the engineers build the model and you manage the sheet set and do all the detailing (nice that your sections will be auto-coordinated to the cuts on the plans... In our situation, the engineers do more of the framing and are ultimately and solely responsible for the content of the drawings no matter who worked on it, so a more flexible flow happens around here between drafts-people and engineers working in the drawings. (we're also small enough that this works very easily. Much bigger and it would obviously start to break-down)

Anyhow, I'm very excited about RS and hope that you'll brush the dust off of your copy and take a stab or 3 at it; the bumps in the road are only bumps. As I've said before, I've thoroughly reviewed Tekla Structures and CSC's 3D+ as well as RS and as far as I'm concerned, RS is the package that is, by far, most geared to getting the work of structural engineering done. Note that I didn't say structural drafting; I mean the business of structural engineering in total. In the final analysis, I think we'll find that RS will beat Autocad + Separate analysis/design packages without question; it's just not easy to see around the learning curve.

Please also believe that I share your concern for the safety of the buildings that "we" design and construct. I can only see RS as an improvement to the process. As it stands now, we have a better chance of missing the transfer of a member size from RAM or RISA onto the Acad drawing now, than with RS. In fact, I committed exactly this error several years ago and, luckily, the wet-weight of the concrete exposed the one beam that was missed. If the model and the drawings had been auto-linked, we would've had a reduced possibility for human error. I'm not suggesting that we trust these things blindly, far from it; but I believe that we should take advantage of every tool available to help us create a safe and fully coordinated set of drawings.

Best Wishes!
-ken

[emile.kfouri]

Thank you so much to Ken, Tom et al for all your comments and feedback. Some very important issues have been brought up about the link with analysis tools. Revit Structure was designed from the ground up to play nice with everyone. (DWG, ADT, DGN, RVT, and all the analysis and design tools that you have on your desktop). In most cases what you see as far as the link to analysis tools are the proof of concept that our partners originally implemented. They are all working very hard to take advantage of all the available API capabilities in R2. We are also working very hard to make sure that by the time R3 comes out the partners will have everything they need to support the workflow that their users demand. If you want to see a specific program linked to Revit Structure or you want to see a specific workflow supported, please relay that to the analysis and design software providers and post it on AUGI for us all to talk about. Also contact them to find out what the supported capabilities are of each program. They vary buy product and company.

In short what you see now is simply the first pass by our partners and us. Tom put it quite well when he explained how the engineers are starting to be interested in Revit Structure as they learn more about what it offers. Autodesk and our partners are also constantly talking to our users to see what they need and how we can continue to improve the program and help address their needs.

You have a great opportunity to influence how these analysis and design tools will work with Revit Structure.

Emile
Revit Structure – Product Design Lead

[gkite]

Hi,
I have been seeing things evolve in my office for two years. At first we just started modeling in the original Revit package (5.1 through 7.0). Of course, there was no analytical link then. The engineers were not very involved in the production of the physical models then. But they started seeing that BIM and modeling could produce a more accurate and coordinated set of construction documents.

But now that RS2 is out and the analytical link has been established I see they are taking more notice. It is a "paradigm shift" in workflow, and in a busy office not an easy thing to do.

This is encouraging as we are just now beginning to involve our engineering staff into our leap into RS and they certainly have some concerns. It does however appear that the more we expose our staff to the benfits of collaborating our workflow within the same model, the more obvious the advantages become.

I am also anxious for the analysis software partners to complete (or at least refine) their work on the links to RS as I see that being the largest selling point to our engineering staff. I understand when Emile explains that what we have seen thus far is a first pass but the ability to transfer the data from the RS model to the analysis software and then back again (and again, and again) is critical in my being able to implement RS companywide.

[David Sammons]

...So, what i'm getting to is simply that less "work" should be done in the analysis
packages and more done in RS...

I just started my first 'real' project where I will have a chance to use RS and the interface with ETABS. The project is a four story steel frame building and I plan to do as much of the modeling in RS and then export to ETABS for the analysis and design.

I will keep this thread informed on how this goes. Hopefully, I can have most of this done in time to share at AU.

[Paul Andersen]

This is an excellent thread. Thanks for getting this one started Tom and to all who have contributed thus far. Over the past 8-10 years our firm has been utilizing several software packages with our primary goal being an integrated analytical model and construction document set. We've had mixed results to this point with most schemes either completely breaking down or becoming too cumbersome to use somewhere after the initial design development and into the early construction document phases of a project.

Revit and RS has caught our eye for several reasons. At the technician level we see the power of the parametric engine. We can be confident that the construction documents are fully coordinated and are able to show views and information that wasn't possible before. On the engineering side we immediately saw that the RS Team was on the right track for integration with a wide variety of analytical software packages. We are currently in the process of transitioning our entire technician staff to RS. The engineers are starting to see the power of Revit and are becoming more interested.

In discussions that we have had with our reseller, analytical software developers, and the RS Team it is our understanding that the RS Team has provided the API and is willing to work with any analytical software developer on a link. Thus, the ball is in the analytical software developers court to make these links happen and during this linking process will probably spur some changes to RS. The analytical software developers are primarily responsible for how much of their software works with RS and what features they are going to take advantage of. I think it is ultimately going to be up to the early adopters of RS to help shape the capabilities of these links. We need to be proactive with our analytical software developers and let them know that we not only want a link with RS but help them understand the work flow and features that we are interested in. When we first started asking some of our favorite analytical software developers about a link to RS one didn't even know it existed and two others were aware but waiting to see if RS was for real.

It is important to note that the analytical software developers have to put some significant effort into making these links work and be productive. Some even have to hire new staff specifically to develop and test this link as their current staff is too busy making changes and updates to their core software. Therefore, they need to know that the users of their software are on Revit Structure and that the link to RS is very important to us. Otherwise the link remains a side project for them rather than the priority I think we all want it to be.