Design of Composite Steel Beams in Autodesk Robot

[@donaldkhanye9011]

PART II ….. THE RSAP ENVIRONMENT AND THE PLUG-IN 21:17 😁 LOL, Wise move of selecting the shell model type right at the beginning before anything else! I must confess that, just like the Editor, I was patiently waiting for the usual mess up there 😁. 27:43 to 28:30 Thanks for running through some of the possible errors and warnings that could happen when exporting elements from Robot to the composite beam design extension. It did help me to not get easily discouraged. I have encountered a number of warnings during the export process. Thankfully to the way in which CEE have handled the warnings in this video, I eventually was able to handle my warnings. It appears though that the extension does NOT support beam sections that are not from the AISC database. I receive a warning that “None of the selected members could be designed” each time I try to use or to select a beam section from other databases other than the AISC. The extension is working fine for me if I use W-beam sections that are from the AISC database. I could not find a setting in the extension itself to change the supported database [if anyone knows how to, kindly advise]. The only place in the extension where I could choose a different beam section size is under “beam properties” in the Design sub-menu =31:17 on this video (only select W-sections are available there to choose from). Alas, I can only hope that Autodesk will improve compatibility with other sections from other databases in future releases. The extension appears to be a good extension. The “Design” options and the “Report” are quite neat. The “Design” options in the extension can also be directly used to design a steel beam without composite action (much in the same way of thinking as the nice and cool idea that was communicated by the CEE at 31:38, thank you CEE for sharing this practical approach and tip). The extension can also send back and automatically update the RSAP model with the beams that it has designed. From what I could gather (I may be wrong); The extension currently only supports simply supported beams (i.e., the beam with +ve (sagging) bending moment arrangement). It has its own internal engine that it uses to calculate the internal forces from the load cases that are mapped directly from RSAP. It appears that it also uses its own load combination factors (I changed the Codes for Combinations from Job Preferences and this did not seem to make a difference in the extension combination factors. The extension did not even allow me to change the combination factors manually in the extension except for the one custom load combination and its associated combination factors which the extension does allow a user to change). I noticed an option in the extension menu itself under Edit>Composite settings> Design Tab, to change the source of “Internal (presumably design) Forces” from the extension own Internal Engine to RSAP, I wonder how this will work considering the need for various design combinations that seem to be embedded or built into the extension? Perhaps I’ll dive in later and see. What was interesting with this option was that when one selects RSAP as the source of “Internal Forces”, the selection triggered two information boxes which required that the user should implement “pinned-pinned” releases on the beams in the RSAP model; and that the slab panels in the RSAP model should be analysed using “simplified trapezoidal and triangular method” as opposed to FE. This in a way answered my next question; I am still going to ask this next question below for completeness: Question: In the RSAP model that was used on this video, the steel beams that are carrying the slab were not released and therefore they had developed some -ve moments near their supports. With reference to the CEE note at 10:35, I suppose it will be correct to say that strictly speaking, one should consider to release such steel beams if one intends to model them (beams) as simply supported beams? Also, the above is not relevant when the extension is set to use its own internal engine to calculate the beam internal forces? I have enjoyed this video and I am looking forward to the next CEE videos. Keep well MJ Regards DK Ps. There seem to be a growing “push” by some viewers for a “full-structure-or-a-full-building”; I certainly hope that these “push” does not derail the CEE from implementing its own contents according to its own pace and plans. In my opinion, the CEE has been excellent so far in selecting and deciding upon the types of topics to present to the viewers and I hope that the CEE will continue to do so under no undue pressure. I don’t doubt that the time for a full-structure-or-a-full-building will come, I just hope that that time is not rushed and that it comes only when the CEE is ready for it, and not at any other moment before that.

[@CivilEngineeringEssentials]

Cont'ed. I still messed up my material, so the editor got me right then and there ^_^ The plug-in is still not really an Autodesk software product, so it is kind of strange what kinds of warnings you might get. I am surprised that it only works on the AISC sections, this makes me a little bit worried as to the "code neutrality" of that plugin. It is still useful, I guess, but now if it turns out that it is code biased, it might limit the usage of this tool for other people. I need to check that thing out. I will get back to you on that. The idea, of preliminary design was somehow not well conveyed by me, so the editor had to help me out in basically trying to rephrase my garbled mess into a coherent method. Yes, I came to the same conclusion that +ve is only considered. Which kind of makes sense. It does have its own calculation engine, as seen by the "neatness" of its moment diagram. You know that moment diagrams when beams are connected to shell elements look kind of broken up into piees. Oh, so it is code biased. That is really sad. But at least the idea of taking values from RSAP is good. I second your point, I have to dive into it too. Please note that this exact thing is what my goal is with creating the CEE channel, explaining things to put you on the beginning of the road of exploration, where you feel intrigued enough to check out the depths. I am really happy that I am getting this reaction from you, it honors me. Stay amazing like this. Oooooooh I missed to mention that!!! The negative moment was so small it slipped my mind. You did an amazing explanation here. I am going to pin part 2 as my pinned comment for other viewers to enjoy reading! YOU ARE AMAZING!! THNX Yes, there is a push to do a full structure, and I am preparing it as we speak. It will be a multi-parter where I will be talking about a steel structure first. It is basically the most important and anticipated video. (Now talking about youtube, it is also the most searched video, but I am not rushing it. It is not about the views, but about the viewer. It is about being responsible for the info I serve you with.) Anyways, it is a pleasure to read your comments. Oh, and pls tell me if I missed anything or if you have any questions. Keep it up, Good Luck, CEE

[@donaldkhanye9011]

@@CivilEngineeringEssentials Hello CEE, Thanks for confirming some of your own observations regarding the plug-in. It helps to know that I am not alone. Thank you for the compliment, it means a lot to me, and I mean a LOT ^_^ coming from you. The CEE channel is one of a kind; and MJ, you are amongst the Giants that Sir Issac Newtown would have been envisaging when he reportedly wrote that “…. If I have seen further, it is by standing on the shoulders of Giants….”. This is how I feel about the CEE channel and about you as a person. In my opinion, all of your viewers (myself included) are exceptionally fortunate that you are willing to make time for all of us. I am glad to hear that you are not allowing yourself to be rushed. You have done a lot for all of us and you continue to do even more. I’d say that take your time, all the time that you need and work on your own pace which fits into your own schedules not those of anybody else. Long live CEE Channel, and I’ll see you in the next videos. Regards DK

[@donaldkhanye9011]

Hello CEE, PART I This is a very nice and a well-received practical topic. I find your theoretical discussions including the practical and construction tips and the reference material to be unmatched as always. I especially appreciate the mentioning and provision of the glimpse (in CEE style) of all of the important concepts that are involved including the transverse shear and the shear flow equations; and the significance of the type of construction of the slab on the slab ability to provide lateral supports to the steel beams. I find these hints to be really helpful in pointing the user to the right directions. 06:40 Truth be told, up until now that the CEE has mentioned this, I never really paid attention to the implications of the Ultimate Limit States approach on the use of elastic analysis theory. Thanks for bringing this up. 10:10 I am covered with regards to the composite behaviour under the +ve (sagging) bending moment. I have also looked at the referenced text for the case of continuous beams in zones of -ve (hogging) moment. The conclusion from the referenced text indicates that “……. the additional strength gained from considering [the other] composite action [involving the structural steel beam and the longitudinal reinforcing steel in the slab] for negative moment is relatively small. And if the steel shape alone is relied on to resist the negative moment, cover plates are sometimes added to the beam flanges to increase the moment strength….” Question: In consideration of the above conclusion, is it not better to avoid the negative moments all together for designs that involve composite slabs? In your experience, what (if any) would you consider to be practical situations where continuous composite slabs with negative moments are beneficial? Would a consideration that a continuous beam will deflect less than a simply supported beam for relatively long spans be enough to offset the above conclusions in favour of a continuous composite slab for instance? 11:35 🤣 “……all engineers could use software, MOST of them will not blunder anything….” 🤣 I must say that with every video release by the CEE channel, this statement is becoming truer and truer by the day (week), one video at a time. Better still, the CEE channel is levelling the knowledge playing field through clear discretization of the underlying principles and concepts for various subjects. Consequently, the goal post for “a competitive edge” is constantly shifting with the CEE channel…. all aboard! hop on! … 🚉🚅 Comment continued in PART II.....

[@CivilEngineeringEssentials]

Hi there Engr. DK, Happy you liked the video. Having a small blindspot with regard to implications of elastic theory and ULS design is totally fine. I have to remind students and professionals alike about it. It is great you checked out the reference text, it really contains a lot of cool info that would complement the tutorial. For negative hogging moments, indeed cover plates are sometimes added to the strength. About your question: Well, yes and no ^_^ Sometimes, negative moments are a must due to stability reasons (a rigid joint in a frame as an example). But I still would - as a designer - avoid negative moments wherever possible. Why? 1) Composite action 2) beams -> girders -> columns -> foundation Once again, happy to read your comment and your feedback, it helps a lot actually. Oh and sorry if my comment might be a little bit dis-organized, as you know, I read your comment and write the answer immediately. It is quite good to be honest. Those discussions actually help me cover points I have missed in the video. Huge thnx to you.

[@donaldkhanye9011]

@@CivilEngineeringEssentials Hello CEE, Thank you so much for the comprehensive feedback. I do not find it to be disorganised at all, the information that your feedback contains is to die for. I love that you are always honest with your experiences and opinions; your response is on point and it is practical. The explanation of a scenario of having a continuous beam which would cut the continuity of the column is clear and it is very much appreciated. I hope that perhaps in some future videos (and if an opportunity presents itself) this scenario is something that could be explored, modelled, and designed to serve as an example of this concept in practice. Your use of typical “load-paths” in order to illustrate what is being discussed and to help the viewers with an even better understanding and visualisation of what is being talked about is quite effective, keep it up. I also thank you CEE, our discussions are helping me a lot, and I do mean a LOT ^_^ (you are helping me a lot). I really like the person that I am becoming because of your channel. Thank you and keep up the good fight. Regards, DK

[@youyoutarikt7015]

Thanks for sharing you're the best

[@CivilEngineeringEssentials]

most welcome. Stay tuned for more content.

[@abdulrahmanabdullahi605]

Please make a full building analysis and design

[@CivilEngineeringEssentials]

definitely. It is going to be about steel first.

[@The_Civil_Lab]

Amazing! the only video on KZbin and very useful to this topic! I have a question please : Does the steel beams fixities need to be pinned-pinned or leave it to default??? thank youuuuuu

[@CivilEngineeringEssentials]

Hi there, thnx a lot for your comment. It honors me to know that those vids benefit you. Now to your question, not sure what you mean, so allow me to state what I think you mean and answer it. (Feel free to clarify more) So what I understood is: you are asking about hte connection between the beam - column and beam - beam? if that was the case, then the answer is: "It is totally up to you" You would think: wait a minute! How? Well, if you decide (yes, it is ur decision BTW) to keep the beam rigidly connected to the column (or beam), then this will have implications on your connection design, which would make it moment resistant and would further complicate its design. If you go for a pinned connection, this makes the connection design easier and less complicated (just 2-4 bolts on a bracket) I hope I was able to understand your question and provide information about it. If I missed your question, please feel free to clarify or even mention a time-stamp in the video which relates to your question, I am more than happy to answer. Regards, CEE

[@The_Civil_Lab]

@@CivilEngineeringEssentials Thank you so much for the detailed answer! it's exactly what I'm looking for!! I subbed to your channel. This is the true spirit of an engineer which is rare. Even my sniors don't have this analysis and logical reasoning, you're a gold mine. Thanks again!!

[@CivilEngineeringEssentials]

You are most welcome. I forgot to say that I recommend pinned pinned Because constructionwise we can keep the column a continuous element So we construct those first, then connect beams to them. Plz consider sharing the channel. It helps a lot 🌹

[@jesuscandea512]

Hi dear CEE, love this pluggin thank you very much! PD: you lost an opportunity to view the “erratic deformation” between slabs and beams haha

[@CivilEngineeringEssentials]

You are most welcome. Oh ^_^, I guess I had "tunnel vision" and was focusing only on composite stuff. Great to know, I will check out the deformations using the same structure again, and maybe prepare a video with that regard. Thank you very much for all your support. Regards, CEE

[@mwangibenson5199]

kindly adress the buckling parameters in member types because i think that's the elephant in the room

[@CivilEngineeringEssentials]

I agree 100%. It is going to be covered in the industrial warehouse series. Regards, CEE

[@mwangibenson5199]

@@CivilEngineeringEssentials thanks. Will appreciate