Nice video, thanks for posting. Good to see that others also run into the same warning and error messages that attempt to derail your model! A CFD wind application series as you mentioned would be excellent as there is lack of this even on the RSA website, just a suggestion. Keep up the good work! 👍
Thnx for watching. Of course, warnings and errors are the "dark side of RSA" that many tutorials just do not want you to see. Here in CEE we keep it real and try to show "real applications" with all of their "problems"
Hello, Doctor, Thank you for the informative videos. I have a suggestion, although I understand it can be a bit tedious to apply multiple cases. If I apply loads as per the code, I should consider applying four cases of wind loads to cover the entire structure. I acknowledge it might seem meticulous, but it's crucial, especially in the case of irregular buildings. Additionally, I've previously used Advance Design . We can export the building to Advance Design, and it will generate all the necessary wind cases. You might want to check it out, as I read about this feature on the Autodesk Robot website. Advance Design excels in generating wind cases.
I totally agree. That is why I - after this video - believe that the best course of action for wind load calculations is to use the RSA simulation if the code allows it. Because what I have done here, is nothing less than pure torture ^_^.
Dear Dr.CEE, In the realm of code, there's a notable absence of explicit mentions regarding CFD, but I think that ASCE recommend Wind tunnel test when it comes to skycrapers. However, it's essential to recognize that engineering extends beyond code boundaries. I've observed, especially in my second year of structural design, that numerous scenarios fall outside code provisions. The dynamic nature of codes, particularly the evolving ASCE code, underscores the need to go beyond rigid adherence. While my expertise lies in Eurocode, I appreciate the significant contributions of the American Society of Civil Engineers (ASCE), which actively responds to market needs with ongoing updates, especially evident in the ever-changing geotechnical field.
Hi drCEE Would you do some wind tunnel test on this building? Another thing… what are supposed to be kinematic constrains? I used to deactivate that option ty as always!
It might be beneficial to compare actually. you just gave me an amazing idea for the next video. As for kinematic constraints, it is just a cool way of saying that: the displacement, velocity and acceleration of two points are constrained In less complicated terms, two points (that are generated due to incoherent meshes) are made coherent by having them act as a single point. Say you have point A and point B. if you constraint then kinematically, then if point A moves a distance in x and y and z, then point B will follow it identically. Of course, there is also velocity and acceleration. You might think that "there is no need, we are calculating this using a static calculation". You are right, of course. Now plz note that the programmers of RSA have actually constrained the velocity and acceleration too. Although we do not need those constraints in a static analysis, if we use a dynamic analysis (which is available in RSA) then it would become active. Hope it helped< CEE
Hello Dr, Feel your pain regarding the the tedious nature of applying wind loads manually, but I think it is maybe a good excercise to visualize and understand what exactly we calculate compared to letting the software do it for you. However, I do hope there are improvements to this aspect in the near future. Great video, as always ⭐️
@CivilEngineeringEssentials I may be mistaken, but why didn't you create one cladding for the entire face of the building instead of separate panels? Thanks
@@YashivYash you totally can. But it will be a pain to put the loads on it. Because if you simple use "distributed on surface" load, then the entire cladding gets the load. In order for it to be floor by floor, I drew cladding by cladding.
But here is where you are right, you can use 1 cladding for the entire side per story. this is good. I did not because there were already some shear walls. So I thought ima do me panel by panel.
Dear CEE, Thanks for your VDO, after we apply wind load & run Analysis, does Autodesk RSA have option to check the stability of structure? or Check the column sway or non-sway in our structures? Best regards, 🙏🙏🙏
If you mean the stability in terms of supports, it does that. but I think you actually ment the stability in terms of story drift and sway - non sway> I do not think that RSA does that. But I still suggest that you simply check the story drift and the total drift against the code limits. There is a code limit (depending on your code) for the lateral drift between the top and bottom of a story. Furthermore, there is a limitation for the total horizontal drift of a story. (I think it is a ratio of the height). As for sway and non-sway, you can use your judgement or you can use the equation of the stability index in the ACI code. Here is an out-take of the ACI code: "ACI 318-19, section 6.6. 4.3 states that a structure is considered to be non-sway (braced) if one of the following conditions are satisfied: If the increased end moments of columns due to the second-order effect is not greater than 5% of the first order end moments. When a stability index (Q) does not surpass 0.05." Now to explain this gibberish, basically the P-Delta moment should be less than the primary moment. Meaning: the extra moment from gravity loads due to lateral movement (P is gravity load- Delta is lateral movement) should be less than 5% of the primary moment (horizontal force x story height) if that is the case (secondary moment < 5% primary) you have a non-sway frame Otherwise, sway. Now you might see why RSA does not do that. It is pretty complicated to program it in a software. Regards, CEE
Thank u for the video, Sir Great video with stunning explanation, hope u doing well and stay healthy. Anyway if u have time, could you check ur email, I sent you my RSAP file as ur request that day, already solve the problem, but curious about the spiky moment, also i read couple of Autodesk Forums online, that said it's because I'm offsetting my beam to not be in the center of the grid level but on the bottom of it (upper beam). Because i want my actual level is my top surface of the beam. I'm giving the idea, if u want to make the video that talks about offset beam, slab and column and so on to explain what is the purpose, the relation to the internal force such as moment, shear, stress, normal, deformation and so on, and the comparison of with and without the offset. Also I'm struggling to learn how apply the T beam and L beam in RSAP, because my college project actually using it and when i provided the reinforcement and run the calculations, it said "the slab section was not transformed to the flange of T section robot structural analysis" I'm frustrated haha, i read the forum, watched hours of video that didn't even solve the problem, why am i design the T-beam, if the reinforcement just for a rectangular beams 😢. Here's i give the idea again if u have enough free time to make the video that special talks about the T beams and L beams. So sorry for the long comment, cus u're my fav yt channel for learning the fundamental concept, also I'm really enthusiastically learn more about the robot to apply my theory in college. Thank you so much sir 🙏🏻😇
I just checked my email. It seems it landed in the spam folder. Sry bout that. did not notice it. Yes, offsets do tend to have this crazy problem. It is because the offsetting causes rigid links to be generated between the beam and the structure. The spiky moments is due to those rigid links. I actually have a video discussing offsets on this channel, might be beneficial. For T beam and L beams, I saw that you have already defined successfully a T-beam in the file you sent me. But it seems that there is a problem with regard to the design of those Beams. I will definitely make a video about them. Consider it done. No need for frustration ^_^. I will check it out and make a video about it. Even if it does not work, I will make a video saying that this is not working. At least people do not need to search too much about it. Thnx a lot for being around, sorry for the late reply. No matter how long the comment, I will check it out. Regards, CEE
