Modeling a Building Slab With SAP2000 - Property Stiffness Modification Factors
Modeling a Building Slab With SAP2000 - Property Stiffness Modification Factors
(OP)
To model the floor and roof in a building I was looking at the SAP2000 tutorials for guidance. The tutorial mentioned to set the f22 modifier = 0 in the Set Modifiers (please see attachment) because this prohibits in plane axial loads. Trying to get a better understanding of why this is required, appreciate your assistance in helping me clarify why this is required.
Also, there is no need to set any other modifiers to 0?
Thanks
Also, there is no need to set any other modifiers to 0?
Thanks





RE: Modeling a Building Slab With SAP2000 - Property Stiffness Modification Factors
RE: Modeling a Building Slab With SAP2000 - Property Stiffness Modification Factors
Where did the tutorial come from? Was the tutorial created by CSI? If so, do you have a link?
If you want to design reinforcement for the slabs, you'll need to manually draw or define section cuts in order to obtain integrated shears and moments.. that, or export the slab into SAFE for design
RE: Modeling a Building Slab With SAP2000 - Property Stiffness Modification Factors
http://www.csiamerica.com/products/sap2000/watch-a...
Thanks
RE: Modeling a Building Slab With SAP2000 - Property Stiffness Modification Factors
Normally in designing slabs you would not use modifiers unless you want to account for cracking by assigning modifiers to the moments of inertia. In-plane stiffness may also be modified, but typically it's the same modifier in both in-plane directions if the engineer for some reason doesn't want to fully take credit for the slab's in-plane stiffness.
Use Edit menu mesh or assign automesh options to control load distribution along with assign area load options to make the load act one-way or two-way. Section cut tool is useful for obtaining integrated shears and moments for design of reinforcement. SAFE is a great tool for slab design since it will automatically design top and bottom reinforcement as well as do the punching shear checks.
RE: Modeling a Building Slab With SAP2000 - Property Stiffness Modification Factors
Just looked at the video and noticed, and as you mentioned it was for a slab on a truss. In my case, the floor slab is for a building and its on wide flange beams.
In the video the Membrane f22 Modifier is set equal to 0 to prohibit in plane axial loads and the stiffness factors of the roof area objects is modified so that they will not act as flange for the top chord of the trusses.
Just want to confirm, so for my case I will keep all the Property/Stiffness modification factors equal to 1?
Thanks
RE: Modeling a Building Slab With SAP2000 - Property Stiffness Modification Factors
RE: Modeling a Building Slab With SAP2000 - Property Stiffness Modification Factors
Would really appreciate it if you can provide some guidance regarding the Property/Stiffness modification factors for both the composite beam and concrete only, for my information.
Thanks!
RE: Modeling a Building Slab With SAP2000 - Property Stiffness Modification Factors
RE: Modeling a Building Slab With SAP2000 - Property Stiffness Modification Factors
Really appreciate your help
RE: Modeling a Building Slab With SAP2000 - Property Stiffness Modification Factors
SAP will automatically account for weight and mass of elements modeled including your deck, so if you want to assign weights from a vendor table for the filled deck, you might consider assigning property modifiers to your filled decks to zero out the weight and mass which you substitute with assigned area load from vendor. You can have the SAP mass model based on loads instead of modeled elements and assigned masses.
SAP has some steel design assignments for camber and camber limits that you might be able to utilize for your design.
RE: Modeling a Building Slab With SAP2000 - Property Stiffness Modification Factors