Modeling and Design of RC Buildings in Autodesk Robot | Part 10: More Loads and Mesh Check

[@donaldkhanye9011]

Hello CEE, I love the honest discussion regarding the wind loads and the RSAP “wind tunnel” simulation, and I 100% agree with every sentiment expressed in that regard. It is indeed unfortunate that some easily allow the “nice, cool, and colourful simulation outputs” to cloud sensical engineering judgement. Thank you for digging into this and for sharing same. The “Garages - passenger vehicles live load of 1.92 kPa on the ASCE” seem to be "correct = same with other codes". The Code in my region states 2.0 kPa for the same Garages and parking areas for light vehicle…. [ Corrections / erratum/ additional information] : for the imposed loads on garages and parking area for light/passenger vehicles (vehicle with gross weight of less or equal 30kN), Eurocode 1 provides the designer with a choice to select imposed load within the range 1,5 to 2,5 kN/m2…..CEE approach in this regard does highlights the importance of always being wary and cautious of the real life circumstances that are likely to occur on the particular structure under review….I had always expected (and used) one single value from the code….. clearly it is more “realistic” to be flexible and to consider the likely kinds and types of vehicles which the structure that is being designed is going to carry and then select the loads which best represent that particular situation….. 08:42 Editor CEE: LoL 09:06 (This is my current culture - but it could evolve) - “Brickwork walls, blockwork walls, etc.” = linear loads on slab; whilst for “timber / boards partition walls or other relatively lighter walls” = equivalent partition load. CEE is correct, this is one of those things that require the designer judgement depending on the particular structure specifics and the deemed acceptable levels of accuracy that is required. Designing for and accommodating future changes or alterations in use and in walls layouts (where the affected walls are not part of the lateral loads resisting system) is a huge influence of how to assume to apply these wall loads. 11:03 Hello Baby CEE ^-^ The current load application trick using the load table combined with the previous video grouping of the elements are very nice and welcome good stuff indeed, they represent (but only a few of) some of the many pecks of being part of the CEE channel community. 17:47 Case-in-point: Yes, do make a group, doing this can only help with future selections. 17:34 Yes, the voice sound is much better now (and it is crisp 😁🎶 ), thank you both and thank you CEE Editor for tweaking the sound settings! 21:25 First Run:🎉 Congratulations are in order for this milestone, very nicely and well done to you CEE🎊. Thank you for the rundown of the warnings from the first run and for the overview of the generated mesh (including the reasons for the conglomerations of the mesh elements at select edge points). The inclined (roof) surface reminds me of the earlier spiral/helical staircase model which was successfully done here at the CEE channel. Off topic (I just could not resist): When you mentioned “Triangles - 24:25” I am thinking are we talking CST or LST ??? then I quickly realised that we are simply just talking about two triangularly shaped slabs that can be meshed with any other shaped finite element (elements such as CST, LST, QUAD, etc.) Question: What in layperson terms is being meant by the warning about “cohesion of the calculation model…….” What occurrences, or omissions (if any) in the model would cause this warning to appear? i.e., what would cause the necessity for a “…..definition of the kinematic constrains….” 25:00 Yes, exactly, CEE have nailed it, I could not have put it any better myself…..should add the line…..FROM ZERO to HERO Lol. Truth be told, this (the CEE channel) is the only place on this platform where the necessary evils, the UGLY realities, and the whats nots are (efficiently and practically) dealt with and are fruitfully discussed and engaged. The CEE channel is unprecedented, it is second to none in terms of its contents and knowledge base; and I doubt that there will ever be anything thing like it in the future. The knowledge gap compared to countless other existing civil engineering channels out there keeps widening exponentially with each video that is released by the CEE channel dream team. Interesting issue on the twisting of the current building model under gravity or vertical loads. I’d have thought that this (the twisting) happens when there are lateral loads (wind or earthquake loads) applied to a structure and where the stability of the entire structure is provided for by asymmetrically located /paced lateral loads resisting elements. Something about the structure center of mass not coinciding with the structure center of stiffness. I am very glad that these and many others are some of the upcoming subjects of discussions. I have enjoyed this video and I am looking forward to the next CEE videos. Keep well and kind regards, DK

[@CivilEngineeringEssentials]

Hi there Engr. DK, yep, the reason why I was a little bit late is because I tried to grasp the wind simulation well before I say anything. I need to be accurate and responsible when I say anything. Even if I make a mistake (and realize that I did) I would immediately correct it. Now let me lay my cards on the table for this one (vehicle loads): You see, basements are usually where cars are parked and where stuff is stashed. It happens many times that instead of having a car parked in a place, the place gets tapped (restricted) and some desks or books or server parts are stashed instead. Now I did not mention this in my video as I try to be culture/region/code neutral, and had to give an alternative explanation. The Editor helped me out there, to be honest and in hindsight, I was like: what am I even talking about? but I am happy that the Editor is here to pick up my slack. Speaking of EPL, I worked in 3 regions so far, my first region used EPL regardless, my 2nd region used EPL for gypsum walls (coz they can change) and linear loads for brick-work (like you just said) and my current region just tries to put beams below walls whenever possible, and applies loads on beams directly. It amazes me to see differences from region to region. It is really cool. I was unable to filter out my lil baby from the recording ^_^ it was a crucial info. For the groupings, I even think I had those slabs grouped somewhere, but I went for the load table trick anyway because it was the best chance to show the power of thinking outside the box whilst having a good grasp of what RSAP can and cannot do. Editor took the feedback immediately into account, although I was a little bit late in responding to your comment on that vid. You see, the semester started so my teaching load is ramping up, meaning that I only have weekends and evenings to work on CEE. About triangles, the CST and LST are - for the lack of a better word - axial elements. Their forces are not perpendicular to the plane of that element. The triangles you see here are .. gimme a sec ima get the reference. ... (realtime writing FTW) Discrete Kirchhoff-Mindline Trangles (DKMT) onlinelibrary.wiley.com/doi/abs/10.1002/nme.1620361106 so they are kind of different. thnx for your comment, especially your appreciation of this channel's honesty. There is no "polished amazing superb" model. The channel here presents things as they are, no colorful stuff, no amazing maps, nope. It is the truth. Oh for the twisting, I think I will show it by producing a very simple structure and explain why it would twist, it makes more sense to that. But yes, as you put it, imbalances in vertical supporting elements in as well as CG and horizontal stiffness imbalances is what makes it twist. It is something I see over and over again in my Student work when they submit their project models. I will be covering this issue as soon as I can. Stay tuned for more content, and thnx for being a member of this channel, CEE

[@donaldkhanye9011]

@@CivilEngineeringEssentials Hello Doc, Thank you for the feedback; there is much wisdom within your feedback and it is appreciated. You are correct, a concrete slab (as it is the case in our building model) would require discretization using finite elements capable of forces in all three (x y z) axis directions. Prof Katili seem to have made a huge contribution with DKMT and extended DKQ elements. I currently only have a faint idea when browsing through his two parts journal articles (per the reference) on this; but it helps to know that these things exist out there. I am happy here at the CEE channel and I plan to stay, and stay happy Kind regards, and l’ll catch you in the next one. DK

[@aliahmataliahmat4440]

Thanks a lot for knowledge sharing.

[@CivilEngineeringEssentials]

You are most welcome. Stay tuned for more content.

[@Augusto5191]

Thanks a lot!

[@CivilEngineeringEssentials]

Most welcome. Stay tuned for more content.

[@khaledmoughabbat7870]

Hello, I hope this message finds you well. In my country (Lebanon), the wind standards recommend the following wind speeds for calculations: a. 26 m/s when applying the Eurocode. b. 45 m/s when applying ASCE7-05. c. 57 m/s when applying ASCE7-16. Based on these recommendations, the automatic wind simulation in Autodesk Robot produces varying results, particularly between the Eurocode (with a wind safety factor of 1.5) and ASCE7-05 (with a wind safety factor of 1.6). Given these discrepancies, do you think it is safe to rely on the automatic wind simulation in Robot, or would it be better to calculate the wind loads separately and apply them manually to the cladding? (Note: The designed structures are steel structures, including warehouses and PV canopies.) Thank you in advance for your guidance. Best regards,

[@mujtabatahir7834]

Nice Job man, Learning Alot. Can you do videos on cold formed steel framing as well

[@CivilEngineeringEssentials]

It is a good request, but please note that RSA is really weak in cold formed steel. I had a video about this on my channel, and you would immediately see the glaring problems in RSA when it comes to cold formed sections.

[@mujtabatahir7834]

Also, is it possible that you can do a video series in which we solve AISC design examples one ny one and compare results in both examples and RSA.

[@JPedroso62]

What about seismic action? will be part of the loads in this example?

[@CivilEngineeringEssentials]

Yes. Seismic action will have its own video once the problems that I listed at the end are fixed.👍

[@JPedroso62]

But if you consider a seismic action, you wouldn't check the modal analysis at the beginning with the aim of controlling mass participation. Because I believe that this structure does not guarantee the 90% as EC8 recommends. Thank you for your work, the best I can find on KZbin.

[@CivilEngineeringEssentials]

I will check that out. ^_^ problem is, I try not to overload listeners with everything at once. I try to have my videos be covered piece by piece. Otherwise, I might overlook other practical aspects. I will keep an eye on that. Now please note: I would use American Codes for Seismic Analysis, but I will keep the eurocode in mind. I might forget to mention EC8, so if I do forget, is it possible that you remind me? would help a lot. Thnx a lot for considering my channel one of the better ones. Regards, CEE

[@MichaelSay-e5w]

Hello CEE, As I get so far following your video, I encounter the error of instability type 3. Could you please help me solve this issue or can I send you the model via email? Thanks.

[@CivilEngineeringEssentials]

Hi there. Hm.. that is odd. Send me the model on [e-mail] and I will take a look. Regards, CEE

[@aliomar6441]

Dear Dr. CEE, I have previously conducted a simulation and research as part of my final year project, where I studied wind using the CFD method. If you are interested, I can share our work. We dedicated over a year to this project, and I believe the results from the CFD method are more accurate than any other approach, which I can demonstrate. Sincerely, Eng Ali Omar.

[@aliomar6441]

Using the code is the safe side for us as engineer .

[@CivilEngineeringEssentials]

Hi there Eng. Ali, That would be an amazing point to see. Could you send me the pdf on: [e-mail]? I would check it out and even feature your work on the channel.

[@aliomar6441]

@@CivilEngineeringEssentials that will be great .

[@mihirpatil4513]

Hey. Can you help me also ., as I am doing my master thesis.. where CFD simulation is required.. I am trying ANSYS BUT ITS hard for me 😅to