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luoxy
Posts: 5
Registered: ‎02-06-2012
Accepted Solution

modeling slab with in-plane moment

560 Views, 4 Replies
02-06-2012 08:06 PM

for solid slab subject to huge in-plane moment due to lateral force, what's the best way to model/analyse?

what i can think of is,

 

use plate element, however plate element only give stress (not moment) for in-plane action. thus a separate simple beam model will be required to capture the in-plane moment then the combined effects can be designed.

 

use grillage model, which means to detail my solid slab as series beams?

 

can anyone shed some light on this issue, any experience and ideas are welcome.

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Valued Mentor
tony.ridley
Posts: 652
Registered: ‎09-07-2011

Re: modeling slab with in-plane moment

02-06-2012 09:35 PM in reply to: luoxy

You could use beep beam theory (essentially strut and tie model), which I believe Robot can assist with.........

Or model as a shell/solid then work out reinforcement from the stresses/strains. 

 

 

In the Robot help menu use the following links;

http://docs.autodesk.com/RSA/2012/ENU/filesROBOT/GUID-F78A01FD-259B-4074-A086-592733F0919-1312.htm

http://docs.autodesk.com/RSA/2012/ENU/filesROBOT/GUID-D00F5201-7422-4672-9031-4F974E759E7-1341.htm

 

http://docs.autodesk.com/RSA/2012/ENU/filesROBOT/GUID-9894AD0E-AE09-426D-B867-09835165CB9-1177.htm#G...

 

see pics attached

 

 

deep beams_01.jpg

 

deep beams_02.jpg

 

deep beams_03.jpg

Tony

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Member
luoxy
Posts: 5
Registered: ‎02-06-2012

Re: modeling slab with in-plane moment

02-06-2012 10:01 PM in reply to: tony.ridley

thx tony, i didn't know Robot does deep beam, great!

 

however deep beam alone is not going to solve my problem, isn't it? as separate 2D-plane model has to be built for design of gavity induced moment. and the slab will have to be check for bi-directional bending for the combined effect.

 

do you have any further reference/reading as for the shell/solid route? I am not sure how it will comply relavant design codes.

 

great help, thx tony.

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Valued Mentor
tony.ridley
Posts: 652
Registered: ‎09-07-2011

Re: modeling slab with in-plane moment

02-06-2012 10:15 PM in reply to: luoxy

try the attached file;

 

 

 

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Product Support
pp2008
Posts: 474
Registered: ‎06-23-2008

Re: modeling slab with in-plane moment

02-07-2012 12:12 AM in reply to: tony.ridley

In case of slab with significant lateral loads resulting in in-plane membrane forces (and because of non-uniform distribution of these membrane forces resulting in in-plane moments) it is possible to use in Robot for shell model the slab reinforcement type considering both bending and membrane forces.rc1.png

 

In such case when calculating slab reinforcement it is recommended to use Analytical and not Wood&Armer method:rc2.png

 

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Regards,



Pawel Pulak
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