Slab Property Data Form

Use the Slab Property Data form to specify a name for the slab property definition, the material, the type of property, any stiffness modifiers, the display color, the geometry,  and other parameters.

Note:  ETABS has built-in default shell object properties for a SLAB1 definition.  Additional definitions can be added and those definitions can be modified. Definitions can be deleted. However, at least one slab property definition must exist, even if it is never assigned to anything.

• Property Name edit box.  Use the default or specify another name for the slab section definition. Note that section names must be unique.

• Slab Material drop-down list. Choose the material property for the slab from the drop-down list of defined material properties. Or use the button to the right of the drop-down list to display the Define Materials form and add a new material definition (or modify an existing definition).

• Modeling Type drop-down list. A slab section can have shell-thin, shell-thick, or membrane behavior.

• • Shell-type behavior means that both in-plane membrane stiffness and out-of-plane plate bending stiffness are provided for the section. Please refer to the Analysis Reference manual (Help menu > Documentation > Manuals command) for an explanation of the thin vs thick shell types.

• • Membrane-type behavior means that only in-plane membrane stiffness is provided for the section.

  • Layered  means the slab is layered. When this option is selected, a Modify/Show Layered Slab Data button is added to the form. Click that button to display the Slab Property Layer Definition Data form. Use the form to define the slab layers.

• Modifiers (Currently Default) - Modify/Show button. Click this button to display the Property/Stiffness Modification Factors form. Use that form to specify the stiffnesses, mass, and weight for the property definition.

• Display Color and Change button. The color displayed will be used to indicate the area objects to which this slab definition has been assigned. Click the Change button to display the Color form and select a different color for this definition.

• Property Data

• • Type drop-down list.  Choose the type of slab: slab, drop, ribbed, or waffle. The option selected determines the other parameters required.

  • • Slab -- Use the default uniform thickness for the slab or specify another by typing directly in the edit box.

    • Drop -- Use the default thickness for the drop slab or specify another by typing directly in the edit box.

    • Ribbed -- Specify the overall depth,the  slab thickness, the width of the stem top and bottom, the rib spacing perpendicular to the rib direction, and the direction of the ribbing parallel to a specified local axis.

    • Waffle -- Specify the overall depth, the slab thickness, the width of the stem top and bottom, and  the spacing of the ribs parallel to the slab 1 axis and the spacing of the ribs parallel to slab-2 axis.

Display the Slab Property Data from as follows:

1. Click the Define menu > Section Properties > Slab Sections command to display the Slab Properties form. Then do one of the following:

• • Click the Add New Property button.

  • Highlight an existing deck definition and click the Add Copy of Property button or the Modify/Show Property button.