Great explanation on applying the bending moment to bolted bending moment end plate. I was confused on how I should apply the bending moment in this scenario before I watched your video. Now Im on track to solve the final question to my final assignment for my final year structural engineering class.
This is very clear and concise but totally disregards the effects of bolt pretension, which in reality would have a large effect on the tension felt by each bolt. This assumes that each of these bolts is basically installed to a loose finger tight. I would love to see a follow up video that takes pretension into account.
Zachary, in case of preloaded bolts tension in the bolts doesn't change until fracture, so it's constant during the time of loading until tension, which should arise from external loading, exceeds the preloaded tension. This is due to the redistribution of stress between the connected plated. It's a tricky feature, but you should understand this. Preload in tension bolts doesn't cause any overload as long it is in the standard limits (in EN 1993-1-8 this is 0.7 times the ultimate strength of the bolt times tension area).
Taras Darmoroz Taras, so for a slip critical connection, bolt tension from moment can essentially be neglected as long as the calculated tension doesn’t exceed bolt pretension? Is this right? This makes sense to me. Does this mean that the allowable stresses for slip critical connections are derived from the bolt pretension?
I have read many books but iam unable to understand this topic, but after i saw this video clearly knows what it is.Really great work sir!!!!Thanks a lot..
I appreciate you making the concepts clear, but I do not understand why we should multiply for compressive force twice when it is already multiplied for calculating the tensile force of the bolt.
Hi kumar shantveerayya ikkalkiswamy, good question. It is important to always think in 3D. The elevation of the bolted connection drawn on paper seems to show just one column of bolts running from top to bottom, but bolts are located on each side of the web of the beam. So when we calculate the force in single bolts, we must remember that they come in pairs. This is where the factor 2 comes into place. I hope that this helps, Mike
When I was a student, I had a hard time understanding this, but your video made it very clear and easy to understand. I was wondering, how do you determine the right thickness of the plate, so you get the linear force distribution in your bolts (Fi = M . zi / sum(zi²) )? The only way I think this is possible, is by using the T-stub method. So I wanted to ask you, can you help with a video on the "equivalent T-stub method" for joint design. I can't find a nice read, that explains it clearly and shows some worked examples. Thank you!
Hi Stefan, thanks for the comment. In industry, in the UK, sometimes the endplate is initially sized by the preferences of the fabricator, or by making it roughly the same thickness as the beam flange, or I think that the Green Book gives advice. If I find myself with time on my hands, I will consider a further video for sure. Best wishes, Mike
Thanks for the thorough video. I'm a mechanical engineer though the curriculum I studied did not cover this type of treatment on bolts (Shigley's 11ed seems to have just one out-of-plane bolt problem), and this seems like a topic particular to civil/structural engineering. Is there any reference material for this method that you'd recommend, such as textbooks or standards?
Hi Nvelopmusic, thanks for the comments. In the UK there are two books used by almost all engineers designing connections: The Green Books by the SCI / BCSA. Text books are few and far between. Owens and Cheal wrote a good one a long time ago and more recently a student showed my one by Alfredo Boracchini - I have not read this one. Hope this helps, Mike
Hello Mike! Your videos have been really good! Are you working in the UK? Secondly, you said the tension from the bolts must equal the compression at the point of rotation. Do you have to also check whether the flange or the web at that location would buckle and crumple?
Hi randomness2376, Thanks and yes, I work in the UK. Yes, probably you will have to check several ways in which the connection could fail. This video concentrates on finding the forces from a simple analysis. The next job is to get to grips with the design by considering all of the possible ways that the connection could fail, Mike
Thanks for the exmplanation. Just for clarification, when the Force values are being calculated at 10:00, does this represent the force being felt by an array of 2 bolts? Or is this force felt per bolt? Aka, do we divide this force value by 2 to get the force felt in 1 bolt at B? Thanks!
Hi Max Mooney, at this point, you are calculating the force in each bolt. So, there are two bolts at the top of the connection and each of these carries a tension force of 62.2 kN. Best wishes, Mike
Very good video!!!! I have a question ...if the base plate for the beam is larger than the beam...what will be the rotation point ? ...the bottom part of the beam...or the bottom part of the plate ? What happen to the bolts that are below the compression point from the beam ??? Thanks and keep the good work!!!
Hi Learning Power, thanks for the comments. Good questions. If the end plate extends below the beam then the answer to where is the point of rotation is "It depends." Imagine that the end plate is incredibly thin (just 1mm thick), then, it would bend really easily and the point of rotation would remain centre line of bottom flange. Now imagine that the end plate is really thick (say 100mm thick, just way too thick), then rotation would take place around the bottom of the end plate, very close to its bottom edge. So now, what is most likely to be the case in reality? Well, most end plates are sized around the same thickness as the flanges of the beam and so are relatively thin. This means that it is safe to assume that rotation takes place at centreline of the bottom flange still. I hope that this helps, Mike
Dear Mike, If any column is supporting 2 steel beams, one connected to its flange and the other perpendicular to it connected to the web of the column, then in such situation the bolted connection of both beams will still have a out of plane bending?
Hi Mike, thanks for your videos, they are clear and easy to understand. I was wondering if you'd also do some examples for in and out of plane loading for weld connections?
What if the loading is UDL? How to measure the distance? Is it need to convert to Point Load? And the distance measure from centre of beam to the face column? Pls help..
Hi Sir, I have one clarification on beam web check. For example if on top of beam steel post is connected with axial load of 50kips and at bottom of beam we have chevron brace connection is there .. the brace component VB is 72 kips .. so please clarify should I check max load or sum of both loads.. for beam web crippling,buckling.bending checks.. Thanks Rajesh
If, towards the paper (inside direction), b1 has more bolts (say 7) and b2 till b4 remains the same number of bolts, does this triangular ratio 5:18 still applies?
Hi Mike Is the values for the bolts at b1, b2 ect at the end of the equation the tensile forces of the one bolt. Or is it the tensile for 2no bolts at that level? Great video clear and concise
Hi Helena, sorry for the delayed reply. The bolt forces, 62.2 kN, 50.6 kN, etc. are the forces in one bolt at a time. This is why these forces are multiplied by 2 when calculating Fc. I hope that this helps, Mike
Great video, but I found that is only one just one way of calculating this problem. I guess you can never be sure how stiffness of elements interfere with each other.
Hi Veron Hrvojic, you are right. This is one approach to out of plane bending which is based on a simple triangular distribution of tensile forces in the bolts. For the bolt rows furthest from the centre of rotation, it would be reasonable to adjust this distribution to increase tension in some bolts as long as there is sufficient ductility locally present. I like the simple model in the video as it allows engineers to very quickly understand how a connection behaves and to do a simple sense check on any computer calculations. The calculations to adjust bolt tensile forces to allow for local ductility are likely to be carried out by computer (although the SCI produce an excellent guide to this in the UK which allows the calculation to be done manually or using a spreadsheet). Thanks for your comment, Mike
Hi Rajesh J, I suggest that you visit www.steelconstruction.info/The_Steel_Construction_Information_System and then take a look at the Green Books. These are industry standard in the UK. If you can get your hands on these, all your questions will be answered (possibly!), hope this helps, Mike
Hi Dude 9gag, hello to Kazakhstan and sorry for taking so long to reply. Yes, you are right. This is just a simple but useful model (please see the comment also above to Veron). I like simple models (I think that they allow me to really understand things better), Mike
Hi,@@mikebather thank you for reply) i asked that question because, at that time i repate hand calc. And checked this simple model in idea statica. Results was little bit different aprox. 20-30percent) thanks again for your lessons.
Hi Mohammad Twaha Jaumbocus, thanks for the question. The method outlined in the video can be used wherever there is an out of plane moment applied to a bolt group which can rotate around a single stiff point. When designing a trussed structure, I would do my best to avoid bending moments in the members, to make the most of the truss action (with members generally either in tension, compression or neither). If you end up with a moment applied to a member and you have a splice (say connecting two members of the same size), then this approach could be used to account for the tension in bolts due to bending. You would have to combine this with any other tensile forces due to any tension (from the action of the truss) in the spliced member. I hope that this helps, Mike
Hi mass ali, in a word, yes! So in this example a fin plate connection could be a good example of a pinned connection. You can search in Google images for both 'steel bolted end plate connections' and 'steel fin plate connections' to see how fixed and pinned connections look. Hope this helps.
Hi syamthehero, in the UK, we adopt quite a simple approach to connection design. Broadly, most beams are simply supported and typically have fin plate or flexible end plate connections. These connections are not designed to carry a bending moment but instead are designed to rotate just a little to prevent any moment developing at the connection. This allows beams to be designed as simply supported. Occasionally, moment connections are needed in steel structures and in these situations a stiffer end plate connection is typically used which can develop a bending moment. Beams supported this way are designed as having fixed (or partially fixed) ends. I hope that this helps, Mike
Hello Sir, if I have applied a bolt preload to each of these bolts, how would that affect the total tension force experienced by the bolts during this applied moment?
Hi DcWaves, If I place a steel bar in tension and then add more tension, I can simply add together the two tensile forces to find the total tensile force in the bar. Bolts are no different. Hope this helps, Mike
Hi d Suji, around 5 minutes into the video I multiply a long equation by two. This is because there are two columns of bolts fixing the endplate to the column - one on one side of the beam and one on the other. So, as there are four bolt rows (b1, b2, b3 and b4) in two columns, there are eight bolts in total. I hope that this helps, Mike
Brilliant video, clearly explains what I needed to satisfy a customer. Thank you very much
Excellent, simple and clear! Awesome!!!
I really don't no why some people are disliked this excellent explanation....anyway the way of teaching is wonderful Mike...
Well put mate!
you speak very softly, but you share great knowledge in a very clear manner, thank you
One of.a kind presentation ! I've been looking for this for a while
Thank you so much Mike Sir for making such a wonderful video. The explanation with visual representation won my heart.
Very helpfull and well explained video.
clear, concise, & informative illustrations, thank you Mike!
Great explanation on applying the bending moment to bolted bending moment end plate. I was confused on how I should apply the bending moment in this scenario before I watched your video. Now Im on track to solve the final question to my final assignment for my final year structural engineering class.
Hi Matthew Trent, Great News! Good luck with the rest of your assignment, Mike
Great explanation! Thank you very much!! Wish there were more videos.
Excellent illustration! Thanks, Mike!
Many thanks for the excellent video!!! Very clear, precise and easy to understand.
This is very clear and concise but totally disregards the effects of bolt pretension, which in reality would have a large effect on the tension felt by each bolt. This assumes that each of these bolts is basically installed to a loose finger tight. I would love to see a follow up video that takes pretension into account.
Zachary, in case of preloaded bolts tension in the bolts doesn't change until fracture, so it's constant during the time of loading until tension, which should arise from external loading, exceeds the preloaded tension. This is due to the redistribution of stress between the connected plated. It's a tricky feature, but you should understand this. Preload in tension bolts doesn't cause any overload as long it is in the standard limits (in EN 1993-1-8 this is 0.7 times the ultimate strength of the bolt times tension area).
Taras Darmoroz Taras, so for a slip critical connection, bolt tension from moment can essentially be neglected as long as the calculated tension doesn’t exceed bolt pretension? Is this right? This makes sense to me. Does this mean that the allowable stresses for slip critical connections are derived from the bolt pretension?
I'm shear I subscribed for bolt moments of exceptionalism, dexterity... and numbers.
Thank you, I did find your presentation interesting.
Thank you very much!
I have read many books but iam unable to understand this topic, but after i saw this video clearly knows what it is.Really great work sir!!!!Thanks a lot..
You are a Legend! Thanks! Helped with my dissertation !
Excellent Simple Great
Thank you for all your u tube tutorials and very much appreciated !!! You are a living legend !!! Rahman
Thank you very much for such a wonderful explanation. mike, could you please add extended moment plate design .
I appreciate you making the concepts clear, but I do not understand why we should multiply for compressive force twice when it is already multiplied for calculating the tensile force of the bolt.
Hi kumar shantveerayya ikkalkiswamy, good question. It is important to always think in 3D. The elevation of the bolted connection drawn on paper seems to show just one column of bolts running from top to bottom, but bolts are located on each side of the web of the beam. So when we calculate the force in single bolts, we must remember that they come in pairs. This is where the factor 2 comes into place. I hope that this helps, Mike
THANK YOU MIKE
you are the best
Very clear and useful. Thank you!
really clear and easy to understand. fantastic video. thank you sir
very clear explination, please do some more!
When I was a student, I had a hard time understanding this, but your video made it very clear and easy to understand. I was wondering, how do you determine the right thickness of the plate, so you get the linear force distribution in your bolts (Fi = M . zi / sum(zi²) )? The only way I think this is possible, is by using the T-stub method. So I wanted to ask you, can you help with a video on the "equivalent T-stub method" for joint design. I can't find a nice read, that explains it clearly and shows some worked examples. Thank you!
Hi Stefan, thanks for the comment. In industry, in the UK, sometimes the endplate is initially sized by the preferences of the fabricator, or by making it roughly the same thickness as the beam flange, or I think that the Green Book gives advice. If I find myself with time on my hands, I will consider a further video for sure. Best wishes, Mike
I like your simplicity.
Wow thanks sir, nice explanation
Great explanation, thank you.
thank you
Super helpful. Thanks sir. I hope that you can make a lot of new videosss
Perfect explanation.
top clear foundation course
Thanks for the thorough video. I'm a mechanical engineer though the curriculum I studied did not cover this type of treatment on bolts (Shigley's 11ed seems to have just one out-of-plane bolt problem), and this seems like a topic particular to civil/structural engineering. Is there any reference material for this method that you'd recommend, such as textbooks or standards?
Hi Nvelopmusic, thanks for the comments. In the UK there are two books used by almost all engineers designing connections: The Green Books by the SCI / BCSA. Text books are few and far between. Owens and Cheal wrote a good one a long time ago and more recently a student showed my one by Alfredo Boracchini - I have not read this one. Hope this helps, Mike
@@mikebather I will see if I can find copies of these. Thank you for the info!
Great 👍
thanks
Hello Mike! Your videos have been really good! Are you working in the UK?
Secondly, you said the tension from the bolts must equal the compression at the point of rotation. Do you have to also check whether the flange or the web at that location would buckle and crumple?
Hi randomness2376, Thanks and yes, I work in the UK. Yes, probably you will have to check several ways in which the connection could fail. This video concentrates on finding the forces from a simple analysis. The next job is to get to grips with the design by considering all of the possible ways that the connection could fail, Mike
excellent... thank you sir i am fan of yours now
Thanks for the exmplanation.
Just for clarification, when the Force values are being calculated at 10:00, does this represent the force being felt by an array of 2 bolts?
Or is this force felt per bolt?
Aka, do we divide this force value by 2 to get the force felt in 1 bolt at B?
Thanks!
Hi Max Mooney, at this point, you are calculating the force in each bolt. So, there are two bolts at the top of the connection and each of these carries a tension force of 62.2 kN. Best wishes, Mike
u r the best
Very good video!!!! I have a question ...if the base plate for the beam is larger than the beam...what will be the rotation point ? ...the bottom part of the beam...or the bottom part of the plate ? What happen to the bolts that are below the compression point from the beam ??? Thanks and keep the good work!!!
Hi Learning Power, thanks for the comments. Good questions. If the end plate extends below the beam then the answer to where is the point of rotation is "It depends." Imagine that the end plate is incredibly thin (just 1mm thick), then, it would bend really easily and the point of rotation would remain centre line of bottom flange. Now imagine that the end plate is really thick (say 100mm thick, just way too thick), then rotation would take place around the bottom of the end plate, very close to its bottom edge. So now, what is most likely to be the case in reality? Well, most end plates are sized around the same thickness as the flanges of the beam and so are relatively thin. This means that it is safe to assume that rotation takes place at centreline of the bottom flange still. I hope that this helps, Mike
wouldn't there be a symmetrical distribution of forces along the center line of the shape ??
Dear Mike, If any column is supporting 2 steel beams, one connected to its flange and the other perpendicular to it connected to the web of the column, then in such situation the bolted connection of both beams will still have a out of plane bending?
awesomeee
Hi Mike, thanks for your videos, they are clear and easy to understand. I was wondering if you'd also do some examples for in and out of plane loading for weld connections?
Hi wmkist, thanks for your comments. I would love to cover welded connections - I just struggle to find time to create the videos. Sorry, Mike
What if the loading is UDL? How to measure the distance? Is it need to convert to Point Load? And the distance measure from centre of beam to the face column? Pls help..
Can you do one video on stiffness of rotation
Thanks a lot! Better than steel structural code book which is 400$ in Canada
what ? no
Hi Sir,
I have one clarification on beam web check.
For example if on top of beam steel post is connected with axial load of 50kips and at bottom of beam we have chevron brace connection is there .. the brace component VB is 72 kips .. so please clarify should I check max load or sum of both loads.. for beam web crippling,buckling.bending checks..
Thanks
Rajesh
Hello Sir, will you please make videos on plastic analysis of Steel.
If, towards the paper (inside direction), b1 has more bolts (say 7) and b2 till b4 remains the same number of bolts, does this triangular ratio 5:18 still applies?
Hi Mike
Is the values for the bolts at b1, b2 ect at the end of the equation the tensile forces of the one bolt. Or is it the tensile for 2no bolts at that level?
Great video clear and concise
Hi Helena, sorry for the delayed reply. The bolt forces, 62.2 kN, 50.6 kN, etc. are the forces in one bolt at a time. This is why these forces are multiplied by 2 when calculating Fc. I hope that this helps, Mike
@@mikebather Hi Mike, no worries thanks very much for getting back to me. Helena
Great video, but I found that is only one just one way of calculating this problem. I guess you can never be sure how stiffness of elements interfere with each other.
Hi Veron Hrvojic, you are right. This is one approach to out of plane bending which is based on a simple triangular distribution of tensile forces in the bolts. For the bolt rows furthest from the centre of rotation, it would be reasonable to adjust this distribution to increase tension in some bolts as long as there is sufficient ductility locally present. I like the simple model in the video as it allows engineers to very quickly understand how a connection behaves and to do a simple sense check on any computer calculations. The calculations to adjust bolt tensile forces to allow for local ductility are likely to be carried out by computer (although the SCI produce an excellent guide to this in the UK which allows the calculation to be done manually or using a spreadsheet). Thanks for your comment, Mike
Anyone know if this applies to bolts in compression, or do the bolts in compression have to equal the tension force.
Thanks sir~
Hi Sir, our explanation using simple thing was so helpful. In same line can u explain the plate bending and buckling shear tab connection.. pls.
Thanks for the kind words Rajesh J, if I had more time, I would love to add to these videos. For the moment, I have no time spare, sorry, Mike
Mike Bather ,
Thanks u.. can u explain when u r free or share some valuable documents
Regards
Rajesh
Hi Rajesh J, I suggest that you visit www.steelconstruction.info/The_Steel_Construction_Information_System and then take a look at the Green Books. These are industry standard in the UK. If you can get your hands on these, all your questions will be answered (possibly!), hope this helps, Mike
Thank you from Kazakhstan! If i understand right this calculation is traditional triangular load distribution. Actual bolt tension may differ isn't?
Hi Dude 9gag, hello to Kazakhstan and sorry for taking so long to reply. Yes, you are right. This is just a simple but useful model (please see the comment also above to Veron). I like simple models (I think that they allow me to really understand things better), Mike
Hi,@@mikebather thank you for reply) i asked that question because, at that time i repate hand calc. And checked this simple model in idea statica. Results was little bit different aprox. 20-30percent) thanks again for your lessons.
nice work than you
Sir, do we use same principle for the end plated CHS bolted connection for tubular latticed structure at splice.
Hi Mohammad Twaha Jaumbocus, thanks for the question. The method outlined in the video can be used wherever there is an out of plane moment applied to a bolt group which can rotate around a single stiff point. When designing a trussed structure, I would do my best to avoid bending moments in the members, to make the most of the truss action (with members generally either in tension, compression or neither). If you end up with a moment applied to a member and you have a splice (say connecting two members of the same size), then this approach could be used to account for the tension in bolts due to bending. You would have to combine this with any other tensile forces due to any tension (from the action of the truss) in the spliced member. I hope that this helps, Mike
@@mikebather Hi Sir, thanks a lot and sorry for late reply.
how to calculate the force in bolts if the load is acting horizontally?
rotate the model
one question how are pin joints designed. they just require to take shear force?
Hi mass ali, in a word, yes! So in this example a fin plate connection could be a good example of a pinned connection. You can search in Google images for both 'steel bolted end plate connections' and 'steel fin plate connections' to see how fixed and pinned connections look. Hope this helps.
hello Mike, can that calculation apply to simply supported beam?
Hi syamthehero, in the UK, we adopt quite a simple approach to connection design. Broadly, most beams are simply supported and typically have fin plate or flexible end plate connections. These connections are not designed to carry a bending moment but instead are designed to rotate just a little to prevent any moment developing at the connection. This allows beams to be designed as simply supported.
Occasionally, moment connections are needed in steel structures and in these situations a stiffer end plate connection is typically used which can develop a bending moment. Beams supported this way are designed as having fixed (or partially fixed) ends. I hope that this helps, Mike
@@mikebather tq Mike for your great explanation.. Really appreciate for your prompt reply..
Bather 4 Life.
Hello Sir, if I have applied a bolt preload to each of these bolts, how would that affect the total tension force experienced by the bolts during this applied moment?
Hi DcWaves, If I place a steel bar in tension and then add more tension, I can simply add together the two tensile forces to find the total tensile force in the bar. Bolts are no different. Hope this helps, Mike
Why that 2 times
Hi d Suji, around 5 minutes into the video I multiply a long equation by two. This is because there are two columns of bolts fixing the endplate to the column - one on one side of the beam and one on the other. So, as there are four bolt rows (b1, b2, b3 and b4) in two columns, there are eight bolts in total. I hope that this helps, Mike
Thank you sir
looks like in-plane bending to me.
really clear and easy to understand. fantastic video. thank you sir
Thank you