Wood-frame lateral design software 6

[cupola21]

I'm thinking about developing a software that can perform wood-frame lateral design. The software will follow the methods as detailed in the book "The Analysis of Irregular Shaped Structures Diaphragms and Shear Walls". It should allow people to import CAD to build 3D model like you normally do in RAM Steel but analysis is driven by analytical methods in the book. It will take care of things like transfer diaphragm checks and horizontally offset shear walls.

The target project will be typical mix-use 3-4 story wood-frame projects. Probably overkill for small residential project I think.

Will anyone be interested in something like this? Or do you use software for wood-frame lateral design?

 

[JoshPlumSE]

That is a lot of work. I'd say that the automated analysis design of wood structures is significantly more difficult than it is for steel and concrete. At least if you're talking about taking the relative stiffness of walls and such into account.

 

[KootK]

I would certainly be interested if you can pull it off well which, as Josh mentioned, is a tall order. The two dominant options that I know of for this are RISA and Woodworks. Both can be time savers but I don't have much love for either as I find them both clunky and cumbersome from a lateral model building perspective.

What I'd like to see is a software package that allows one to build my model by tracing over a PDF. In my opinion, the CAD importing doesn't work anywhere near as well for light framed buildings as it does for steel and concrete. CSD does this and it's excellent. Their software is gravity only at the moment however.

 

[driftLimiter]

I've been talking about making an integrated wood lateral design software for a while now. Even something that just flows like hand calcs for flexible diaphragms and shear walls would be really nice. I think a lot of the 'issues' with making a software like this stem from attempting to use FEA for the elements instead of hand methods for load attribution and deflection checks.

I am game I think you should do it cupola21.

 

[LockeBT]

There was a program (it's discontinued now) called BuildingWorx from structuralsoft. It was a great program and was fully integrated and compatible with AutoCad. It's no longer around

 

[Aesur]

I would definitely be interested. Currently we use WoodWorks Shearwalls where we can, but with it's limitations it's not always easy to use for all multistory buildings and will never work for residential structures (as is), especially only being able to model at right angles. As KootK said, tracing over a PDF is nice, I use that method in the Woodworks software.

 

[Gasma]

Woodworks software is already doing it and its not that expensive. You should give it a try

 

[cupola21]

I agree that turning flexible diaphragm hand calc method into software can be challenging but it is definitely doable, if it is programmed using appropriate data structure. Like driftLimiter mentioned, developing it from FEA approach makes it hard. To do FEA right in wood, you need to model all nailed connections as springs to get the stiffness right. I've done it in Abaqus for research in the past and I could automate assignment of these springs, but it may be too hard to understand in practice.

I also tried RISA-3D and WoodWorks in my projects. I agree with Kootk. Need to input a lot of information to make it work. Modeling isn't very intuitive for me at least. I only use WoodWorks sizer for some LVL beam calcs. For RISA, it is not clear to me what they do with the diaphragm. It seems you need RISA Floor to use flexible diaphragm.

Interesting comment about PDF. I agree. I actually use BlueBeam to mark up my bearing walls, run calcs in Excel and put numbers down in the PDF. I'd love to write a plugin in BlueBeam to automate calculations, but I don't think they allow it. For tracing PDF, would features like node snapping or parallel guideline typical in AutoCAD be important for you?

 

[skeletron]

Oh man. That's a rabbit hole. Would be interested in seeing what you come up with.
I agree the "trace" option would be pretty handy. WoodWorks Shearwalls does have a working version of this but it is, like other smaller details, kind of clunky.
The other observation I have is that, particularly in the residential/low-rise realm, there seems to be some additional leeway for offsets and other geometrical imperfections. A fine-tuned software may "overthink" these and cause odd results.

 

[SJBombero]

While FEA may be overkill, I do see why it is the default tool to automate a diaphragm. FEA has well defined algorithms for dealing with almost any geometry you throw at it. Trying to implement the rational approaches of "Analysis of Irregular.." will require some sort of rational input to "guide" the software. Due to the infinite possibilities of openings and jog, the user would have to define the subdiaphragms and transfer diaphragms. I don't see how an algorithm could be developed to make all those decisions.

 

[bones206]

I saw a Youtube video once on diaphragm design and the presenter showed some in-house diaphragm software at the end. I'll try to find it.

 

[driftLimiter]

Due to the infinite possibilities of openings and jog, the user would have to define the subdiaphragms and transfer diaphragms. I don't see how an algorithm could be developed to make all those decisions.

While I agree that it is difficult, it can't be insurmountable with modern technology. At the end of the day were talking about rectangular regions, perhaps some machine learning or parameterization of user inputs could offer guidance while modeling. I'm not saying it will be easy, but classification of the regions, checks for aspect ratio, expose internal forces and apply to regions, check chords, add subdiaphragms and subdiaphragm chords.

There are more things to consider but not infinite amount of them. I think it will just take a bit(a lot) of logic that is perhaps a bit outside of struct. engineers' normal thinking and approach. I am almost certain that with proper collaboration from other fields the solution is not far out of reach.

 

[bones206]

I saw a Youtube video once on diaphragm design and the presenter showed some in-house diaphragm software at the end. I'll try to find it.

The software is featured in the last few minutes of this lecture video:

https://youtu.be/AFIYaYT2mTs

 

[abusementpark]

There was a program (it's discontinued now) called BuildingWorx from structuralsoft. It was a great program and was fully integrated and compatible with AutoCad. It's no longer around

Agreed. It was only around for a few years, but it was great. We've had to resort to developing our own in-house spreadsheet since then, which was a pain-staking task, but maybe for the better in the long run.

 

[cupola21]

The software is featured in the last few minutes of this lecture video:

https://youtu.be/AFIYaYT2mTs

This video seems to be about rigid diaphragm. I know Enercalc can do some rigid diaphragm analysis, though I don't think it provides diaphragm moment diagram. Do you think it is necessary to have a rigid diaphragm option in a wood-frame lateral design software? Thanks.

 

[cupola21]

Agreed. It was only around for a few years, but it was great. We've had to resort to developing our own in-house spreadsheet since then, which was a pain-staking task, but maybe for the better in the long run.

I'm interested in what BuildingWorx can do, but I cannot find anything about it online, even a screenshot. Do you mind telling me what features it has make you like it? Thanks.

 

[phamENG]

I wouldn't do rigid for wood, but semi-rigid would absolutely be necessary to make it really worthwhile. Distributing loads for a simple, flexible diaphragm is cake and there's little benefit of using software to do it. It's the 3-sided, open front building with a cantilevered diaphragm that's only stable if you consider semi-rigid behavior and some level of torsional stiffness that would be nice to have good software to solve.

 

[Celt83]

Enercalc: rigid diaphragm tool for load distribution to walls/frames only, does not provide correct results if lateral elements are at angles other than 0 and 90 degrees, does not allow modeling of the diaphragm perimeter to check corner deflections.
Woodworks: Can envelope Flexible and Rigid Solutions, Wall panels must be 0 and 90 degrees layout of skewed walls is prevented, great documentation of the results, also shows collector forces.
RISA: Can handle semi-rigid floor as an FEM model.

Programming this is trickier than it sounds there are an abundance of diaphragm types and different nailing's providing different capacities, same goes for the wall panels for a flexible analysis that doesn't play in but a rigid or semi-rigid analysis is going to be non-linear as you'll need to update the wall panel design and stiffness over multiple iterations. The Woodworks tool is really cheap as far as these software packages go, if you have yet to try it it out I recommend it just the see the shear number of options they needed to give you access too to make it work.

I'm making a thing:

http://www.thestructuraltoolbox.com

(It's no Kootware and it will probably break but it's alive!)

 

[bones206]

This video seems to be about rigid diaphragm. I know Enercalc can do some rigid diaphragm analysis, though I don't think it provides diaphragm moment diagram. Do you think it is necessary to have a rigid diaphragm option in a wood-frame lateral design software? Thanks.

Yea, I was just throwing it out there as a potential resource on the programming side of things. It looks like that in-house software had the capability to resolve diaphragm shears and chord/collector forces. This is the firm for anyone interested:

http://www.senecastructural.com/index.asp

 

[milkshakelake]

@Gasma Woodworks does not analyze irregular diaphragms and shear walls.

@cupola21 I've been doing irregular diaphragm analysis by hand and it's a nightmare. I wish a program existed for it. The book you mentioned is also badly written and hard to follow, so a software "helper" would be nice. I'd even like a software for regular diaphragms, since that software is cumbersome and not well automated. Wood design software has a lot of catching up to do compared to other industries. You might even be able to get a grant from Woodworks for developing it, though I guess then you wouldn't own your own work.