Complete

Ram Elements NDS Wood Design/Checking

Currently, the only code available is NDS 2005.  Since we have to submit our calculations for review, having the appropriate code check/design standard is important.  Currently in Virginia, we are required to use NDS 2015.  Some states require NDS 2018.

One of the newest, coolest hip innovations in wood design is Mass Timber.  I know Mass Timber or CLT (cross-laminated timber) is a "Hot Topic" in the press.  I'm guessing that 95% or higher of wood-framed projects DO NOT use this innovative system for framing.  So until Bentley has had a chance to add this tool, I would suggest that it would be reasonable to update the wood design capabilities and code checking from the 2005 NDS to something like 2015 and/or 2018.  As long as it is clear that this chapter of the NDS is not included, I don't think you will find much resistance.  Does this make good sense and for Bentley does it make cents?

Parents
  • Since it's been over 3 years since I first asked for the wood design in Elements to be brought into compliance with current building codes, and this item says that you are "planning to update the NDS design code for the current RAM Elements capability for 2021" and it's now 2022, I thought I would reiterate the need for this. It's worth pointing out that since states legally adopt a model code (with amendments if desired), and that building code edition incorporates various national standards by reference (e.g. AISC 360-16, NDS 2015, etc), our calcs from Elements using the 2005 NDS standard are not in compliance with any of the state building codes.

    There are several items of concern here.

    1) Table data for wood properties are updated with each new edition and some of Elements' underlying data is obsolete now.It's hard to have good output based on outdated properties. It's also hard to trust the output from Elements when it doesn't cross-check with other wood programs that have bothered to update their data in the last 16 years....

    2) The glulam section tables don't include all of the sizes from NDS. Everything in NDS Supplement Table 1C should be available as a section size without me having to create a table of custom sizes to account for what are actually standard sizes.

    3) Elements should have the basic NDS options for glulams as options for design. Besides not having recognized sizes as noted above, Elements doesn't have the Stress Classes from NDS Supplement Table 5A, only the Combination Symbols from the expanded version of 5A. Again, these are valid choices in NDS and should be valid choices in Elements.

    3) Elements calculates several properties incorrectly because it doesn't use the correct value for Emin and hence Emin'. That affects both the Column Stability factor Cp and the Beam Stability factor CL through the critical buckling design values, FcE and FbE, respectively.

    There is certainly a lot of room for Bentley to improve in the area of wood design. There's even still room for Bentley to take the lead. If you updated to NDS 2018/2021, that would be a big start. Mass Timber is a big area right now. We worked on a 5-story mass timber building last year that had large glulam columns and beams, CLT floors, CMU stair/elevator cores for shearwalls, and a couple of steel moment frames in one area. Such a mix of materials in one project is is where Elements really shines compared to steel-only or wood-only programs. Since Ram Connection can be incorporated into Ram Elements, being able to address even some basic wood connections in our Elements models like we do for steel connections would be a very nice addition. And if you've ever used the WoodWorks Connections program, they set the bar very, very low. It wouldn't take much to surpass them in functionality, especially if it could be part of an integrated model like Ram Elements and Ram Connection allows. Just sayin'. But I'm also with SVGregory on this: don't delay release of basic wood provisions for development of mass timber provisions, because I'm a lot more likely to need correct results on a double 2x12 header than I am a CLT floor plate or shear wall. And honestly, if I can't get correct results on that double 2x12, why should I trust Bentley with calcs on a 20.5"x 41" glulam beam or 20.5" square column (a typical beam and column size on the 5-story project I mentioned)? Get the basics correct again so we can trust you there, then expand functionality.

  • Hello Jason,

    Yes, the NDS-2018 component was completed last year (2021) for saw lumber and glulam (maintaining current functionality) and now it is being implemented in RAM Elements to be released in a couple of weeks. Let us check your comments and come back to you ASAP.

  • Ah, OK. It was not very clear in the program what it was using since it showed a Size Factor of 1.0 in the report for most of the SP sections, and didn't list the Fb used. But that's good to know it is still getting handled internally. And that's great on the report. That makes it very clear what it's based on now.  Looking forward to the new release! Any updated ETA?

    Thanks,

    Jason

  • We are currently preparing a release candidate, if it passes all tests then by the end of the week it would be available for users.

  • We are currently preparing a release candidate and if it passes all tests then it would be available early next week.

  • Thanks for the update.  Clear output for the code checking is why I use Ram Elements at least for Steel Design.  There are those other programs that use the "black box" approach.  For Wood Design, I expect the same type output as the steel Design.  NDS has a lot of factors available to modify the basic allowable stresses!

    I am looking forward to the new Ram Elements "no black box" update.  One of the black box programs also has manufactured composites using LVL and PSL from several manufacturers.  Will Ram Elements have any of these composites?

  • Hello SVGregory, we would need to check if we could just use their database. Let's add this as an idea and see if there are more interested . 

Comment Children
No Data