Dear CEE i just love your basics videos, i was wondering about buckling length coefficient, you set it up at 1.00? Maybe It should have been 0.70? Anyway i always had this very big doubt about defining imperfections or not when you are after the alpha cr (according to ec3)? Or even during second order analysis? Theres also an buckling analysis type where you can consider deformation shape, has that anything to do with this? Thank you very much as always!
Hi there dear Engr. Candea, I totally missed talking about the buckling length coefficient. Yeah, 1 is a conservative k. It can be calculated from alignment charts. It is even in the e0 equation of the eurocode (EC3 (ENV 1993-1-:1992)) In my humble opinion, imperfections should be included when the second order analysis is needed and/or buckling analysis. I am not sure of RSA has a fully fledged buckling analysis module. You may do a second order analysis with imperfections to "simulate it" but the fully fledged buckling analysis? not really sure. I need to check it out and maybe do a video on that if I find it. Still, thnx a lot. You are 100% right, I should have talked about k and even explained how the value is decided. I am going to pin your comment for future viewers. I am sure the discussion would benefit them. Regards, CEE
The matter with the initial imperfections mostly apply to the global analysis systems. An unrestrained portal frame or a U-frame action steel foot bridges (think about the top chord) would be a subject to initial imperfections. For simply elements EC 3 chapter 6 applies which takes imperfections into account and effective length would have to be determined. For complex structures and with global analysis, I suggest the initial imperfections to unbalance the structure + P-Delta analysis to pronounce the effects. The simply section check is enough, and no need for effective length for buckling. BTW, A good take again, cheers
Hi there, sorry for the late reply ^_^ Those are amazing points! Thank you for mentioning places were imperfections are to be checked. This helps both me and future viewers see the importance of this tools in RSA> And also, I admit, I missed mentioning the P-Delta effect that would amplify the effect of imperfection. It slipped my mind, kind of was laser focused on showing the way RSA applies geometric imperfections, so I lost the more general picture. Thank you very much, your comment is definitely an important addition. In the end, I am happy you still liked the video. I always feel great enjoy checking out your comments. Regards, CEE
@@CivilEngineeringEssentials You are doing a good job and have to say I value the effort you put in and mostly I enjoy seeing how much passion you put into it. Not many people left with passion into serious engineering. :) cheers
@@CivilEngineeringEssentials i am now practicing robot structural analysis software because of your videos by the way you fast tract and explain it in its simplest way. thank you so much for sharing CEE
once again very thankful to the videos series. dear Dr. when it comes to design of buildings which is better and mostly used ETABS OR ROBT structural analysis ?
Hmm. that is a good question. Now personally I am an Autodesk Fan. But I am not saying the CSI is weaker. The reason why I cover RSA extensively is because engineers may have easier access to it especially during the university years (free licenses for students). Also, in my humble opinion, I think RSA is easier to use. But note: it is just a personal opinion here Regards, CEE
Dear CEE i just love your basics videos, i was wondering about buckling length coefficient, you set it up at 1.00? Maybe It should have been 0.70?
Anyway i always had this very big doubt about defining imperfections or not when you are after the alpha cr (according to ec3)? Or even during second order analysis?
Theres also an buckling analysis type where you can consider deformation shape, has that anything to do with this?
Thank you very much as always!
Hi there dear Engr. Candea,
I totally missed talking about the buckling length coefficient. Yeah, 1 is a conservative k. It can be calculated from alignment charts.
It is even in the e0 equation of the eurocode (EC3 (ENV 1993-1-:1992))
In my humble opinion, imperfections should be included when the second order analysis is needed and/or buckling analysis.
I am not sure of RSA has a fully fledged buckling analysis module. You may do a second order analysis with imperfections to "simulate it" but the fully fledged buckling analysis? not really sure. I need to check it out and maybe do a video on that if I find it.
Still, thnx a lot. You are 100% right, I should have talked about k and even explained how the value is decided. I am going to pin your comment for future viewers. I am sure the discussion would benefit them.
Regards,
CEE
The matter with the initial imperfections mostly apply to the global analysis systems. An unrestrained portal frame or a U-frame action steel foot bridges (think about the top chord) would be a subject to initial imperfections. For simply elements EC 3 chapter 6 applies which takes imperfections into account and effective length would have to be determined. For complex structures and with global analysis, I suggest the initial imperfections to unbalance the structure + P-Delta analysis to pronounce the effects. The simply section check is enough, and no need for effective length for buckling. BTW, A good take again, cheers
Hi there, sorry for the late reply ^_^
Those are amazing points! Thank you for mentioning places were imperfections are to be checked. This helps both me and future viewers see the importance of this tools in RSA>
And also, I admit, I missed mentioning the P-Delta effect that would amplify the effect of imperfection. It slipped my mind, kind of was laser focused on showing the way RSA applies geometric imperfections, so I lost the more general picture. Thank you very much, your comment is definitely an important addition.
In the end, I am happy you still liked the video. I always feel great enjoy checking out your comments.
Regards,
CEE
@@CivilEngineeringEssentials You are doing a good job and have to say I value the effort you put in and mostly I enjoy seeing how much passion you put into it. Not many people left with passion into serious engineering. :) cheers
@@CivilEngineeringEssentials I would be happy if you could work out an arch and present how to do it using all those points ;)
haven't saw this comming... thanks a lot CEE
It had been an idea in mind for a long time. But I just was able to find time to formulate the video ^_^
Regards,
CEE
@@CivilEngineeringEssentials i am now practicing robot structural analysis software because of your videos by the way you fast tract and explain it in its simplest way. thank you so much for sharing CEE
Shout out to the team !!!! Very appreciated
you are most welcome ^_^
If possible, please share this channel with your friends. It helps a lot.
Regards,
CEE
once again very thankful to the videos series. dear Dr. when it comes to design of buildings which is better and mostly used ETABS OR ROBT structural analysis ?
Hmm. that is a good question. Now personally I am an Autodesk Fan. But I am not saying the CSI is weaker. The reason why I cover RSA extensively is because engineers may have easier access to it especially during the university years (free licenses for students).
Also, in my humble opinion, I think RSA is easier to use. But note: it is just a personal opinion here
Regards,
CEE