Modeling sandwich wall in SAP2000

[compe_ad]

Hi everyone! The system consist of two reinforced concrete panels with the insulation in between. Shear connecters are used to connect two concrete panels.
Can you please share ideas on how to model sandwich wall panels in SAP2000? Any suggestions and recommendations will be greatly appreciated.

 

[271828]

If the shear connectors are stiff and strong enough to transfer the shear (VQ/I) between the panels then I would:

1. Compute the MOI of the two panels, including parallel-axis terms.

2. Create a shell in SAP2000 of a chosen thickness. t = sum of the two concrete thicknesses seems to make sense because that would result in the right axial stiffness and mass.

3. Use Property Modifiers to increase the shell MOIs to match the value from #1. Might also use a PM to increase the mass and weight a little to account for the insulation.

 

[271828]

A sketch would help, BTW.

 

[Brad805]

This will depend if they are partially composite panel of fully composite.

 

[compe_ad]

Thank you all! It will be designed for fully composite. But can you also tell me how to model if it was partially composite?

 

[271828]

I'm not familiar with your system. For other systems, I've seen reduction factors to account for partial composite behavior. Some test data would probably be needed to pin these down. In the MOI calculation, the parallel axis terms are discounted by the reduction factor.

 

[Brad805]

For fully composite it is not complicated. Use the equivalent stiffness.

For partially composite connectors it is far more complicated, and few do this. You would need to know the connector style, and have access to the push off test data. Using push off data you can use springs at the location of each connector. From the push off data you can assign the spring stiffness values. Dr. Marc Maguire has led most of the recent research for this. You can find many of his studies online.