Stiff properties

What is the "Stiff" slab type?

Answer: In real structures, there is an extremely stiff region within the connections which join columns and walls to slabs. The "Stiff" elements are stiff area elements in which the software amplifies moment of inertia by 100 times to capture the increased stiffness of these connections.

The effects associated with modeling these increased stiffness properties within connections include the following:

• Deflections are more realistic and less conservative in magnitude.

• Rebar design is also less conservative since reinforcement is designed according to response at the face of the column, and not at the centerline of the support.

• Punching-shear results will change since the stiffness of the areas around the punching-shear perimeter change.