Form: Property/Stiffness Modification Factors
Use the Assign menu > Wall/Ramp Data > Property Modifiers command to assign property/stiffness modification factors to a selected wall/ramp object.
Select one or more wall/ramp objects extending above or below the datum plane (not slabs or footings).
Click the Assign menu > Wall/Ramp Data > Property Modifiers command to access the Property/Stiffness Modification Factors form, which offers the following modification categories:
Membrane: Modify the in-plane membrane stiffness in any of three different directions. A factor of one entered into an edit box will result in the gross stiffness value being used. A factor other than one will linearly scale the stiffness by the assigned factor.
Bending: Modify the out-of-plane bending stiffness in any of three different directions. A factor of one entered into an edit box will result in the gross stiffness value being used. A factor other than one will linearly scale the stiffness by the assigned factor.
Shear: Modify the shear stiffness in two different directions. A factor of one entered into an edit box will result in the gross stiffness value being used. A factor other than one will linearly scale the stiffness by the assigned factor.
Weight: Modify the material weight. A factor of one entered into the edit box will result in the material weight as input in the Material Property Data form being used. A factor other than one will linearly scale the weight by the assigned factor.
Local axes may be viewed by checking the Local Axes check box for area objects on the Set Display Options form. The red axis indicates the local 1 direction, while the green axis is the local 2 direction. For additional information on wall/ramp geometric properties and internal forces, please consult “The Shell Element” chapter in the Analysis Reference Manual (see Help menu > Documentation command, Manuals subdirectory).
Note: If you wish to eliminate a particular stiffness component from the selected objects, it is recommended that you use a very small value rather than zero. This reduces the chance of an instability occurring due to a zero in the stiffness formulation.
Note: SAFE automatically applies an internal f11 modifier of 0.1 to walls to avoid in-plane stiffness in the walls for PT tendons