why when i do punching for corner column robot consider it as edge

[egoze]

helloo 

i am wonder when try to check punching for a corner column robot consider it as an adge and when i change it to edge from the punching window and recaculated the result does not chang

and anther point i have to ask 

robot add steel reinforcment when the punching is not safe, if i do not want a steel reinforcment  what i have to do in the this case to let robote to understand that 

 thank you in advance 

[Artur.Kosakowski]

i am wonder when try to check punching for a corner column robot consider it as an adge and when i change it to edge from the punching window and recaculated the result does not chang

Could you attach the rtd field and indicate which column to check?

and anther point i have to ask 

robot add steel reinforcment when the punching is not safe, if i do not want a steel reinforcment  what i have to do in the this case to let robote to understand that 

Robot only calculates the required area of reinforcement but it doesn't generate it (makes its distribution) so you just may 'ignore' this information.

[egoze]

helooo sir

punching is very intersting topic thats why i asked you for help

why robot conseder the corner column as an edge by default  

you can see 

the file and the pics

[Artur.Kosakowski]

why robot conseder the corner column as an edge by default 

The algorithm which detects the location of a column tries to do it right but sometimes this detection may be incorrect. this is why you can manually change the column type e.g. from edge to corner. Mind the value of bo for the column you indicated is correct (half of the edge one and 1/4 of the internal one)

and when i change it to edge from the punching window and recaculated the result does not chang

As in this case the change of the alpha which is used for calculations of the stress limit is not the governing one. The other formulas keep the stress limit at the lower values tehrefore you can't see the effect of this change directly.

For other questions check:

http://forums.autodesk.com/t5/Robot-Structural-Analysis/Punching-shear-check/m-p/3839964

http://forums.autodesk.com/t5/Robot-Structural-Analysis/Rc-slab-Punching-verification-by-maps-and-rc...

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

[egoze]

 hi sir 

please check the attachment 

thank you

egoze

[egoze]

if you please show me the influence moment in the edge colum in both direction,  espatially  diferance in moment  how can find them , it will help so much in internal column as well 

thank you   in advance

apdate pic 

[Artur.Kosakowski]

Q is calculated based on the stress distribution and the critical section - see the attachment to the message 4 from http://forums.autodesk.com/t5/Robot-Structural-Analysis/Punching-shear-check/m-p/3839964

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

[egoze]

thank you sir 

but still im asking for moment ? how to find it 

regards

[Artur.Kosakowski · Accepted solution]

Check  the value of the bending moment in a column.

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

[egoze]

heloo sir 

sir i read the column moment it was acceptable for me and very close to the strip method

but if we add one story above we will read differant momet , and for 4 story modle diferent reading 

why these differant in  amounts of moment ? which one is correct and image if 11 story building 

 please see attachment and rtd file 

[egoze]

i hope to hear from you soon

[Artur.Kosakowski]

I'm not sure if I understand you correctly. I'd say that the fact that bending moments change when you add more stories is what I'd expect and I'd be surprised if adding columns and slabs above would not change the value of the moment in the columns below. Please mind that Robot calculates the whole model rather than each of the stories (slab and columns below them) separately.

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

[egoze]

sir

exactly.

 but as you know i am checking bunching for each floor 

and my floors are typical  ,  my question as you know is it right to read as what i have done by the pic 

is it right to have differnt in moment for each story for punching moment for similer  story ,,, what i know the punching should be same for typical story 

is right to take the moment for each story or i will choose on of them 

im confused for moment  of punching 

[Artur.Kosakowski]

is it right to have differnt in moment for each story for punching moment for similer  story

If you calculate the whole model then I think it is.

,,, what i know the punching should be same for typical story 

It should be similar with the exception of  a single story one as there is no upper column above the lower one. Looking at your pictures:

4 story - 30.76

2 story - 30.39

You may consider selecting the floor where you have the maximal moments and assuming it as the typical one and then use such calculated reinforcement for all others.

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

[egoze]

🙂   thank you in advance  

i am happy with this