Autodesk Robot Structural Analysis

[#1]

Dear all members,

Please kindly give me a concept modelling for Pile cap desiging in autodesk robot. I used to model as a slab whose thinkness is equal to the real pile cap. The piles are modelled as column under slab and column above pile cap are model as a column. Finally the result of pinching shear is not satified and rc bar is also so high comparing to manual caculation

Thank you so much,

Pisey

[#2]

Hi, I'm not sure how the Robot People would do it so it would be good to know. What we usually do is model the piles as elastic supports and use rigid links to model the full pile behaviour (by adding nodes on the pile periphery and providing rigid links with the center of the pile). As for the column, we use a distributed load instead of a nodal force. Give it a try.

When it comes to modeling anything, there are so many ways, but I think the Robot guys probably know the best way to receive accurate results.

[#3]

You could use the plane stress option but this won't check for required reo or for punching shear automatically.  

However it will give you the stresses that you need to provide reo for.

I think if you model it as a slab element it won't be accurate as Robot will assume the slab/shell is a flexural member.  

I think you normally use a strut/tie method for pile caps which will result in different amounts of reinforcement than you'd get from flexural design analogy.  

Tony

[#4]

Dear Pisey,

see the link: http://forums.autodesk.com/t5/Autodesk-Robot-Structural/Pile-Caps-with-Robot/m-p/3042304

Thanks

Gustavo

[#5]

Dear Tony,

yes, I think you have reason. anyway, do you think Robot can design element in Struct and Tied analysis methode or not? could you give me some idea, if i want to calculate Pile Cap by Robot as i want to check punching shear also.

Thanks,

Pisey