The Slab Property Layer Definition Data form is very similar to the Wall Property Layer Definition Data form. The following applies to both section types.
Use the {Slab, Wall} Property Layer Definition Data form to define a layered {slab, wall} object.
Parametric Quick Start button. Click this button to display the Quick Layer Definition Data form. Use the form to specify rebar material and size for a single layer or the top and bottom of a two-layer concrete slab or wall object. After the parameters have been specified on that form, the data will transfer automatically to the spreadsheet area on this form (i.e., the cells for the Layer Name, Distance, Thickness, Material Type, and so forth on this form will be filled automatically). Modification to the parameters can be made by direct entry into the appropriate cell, as described below.
Alternatively click the Add button to begin work in the spreadsheet area of the form without using the Parametric Quick Start button. As necessary, use the Add button to add additional rows of data after using the Parametric Quick Start button.
Layer Name edit box. Use the default or type a revised label for the name of the layer (e.g., 1, 2, 3 or Top, Middle, Bottom).
Distance edit box. Enter a value for the distance from the shell reference surface (shell object joint location plus offsets) to the mid-height of the layer. Positive distances are in the positive shell object local 3 axis direction
Thickness edit box. Use this edit box to specify the thickness of the layer. Note that the thickness of the section depends on the thickness specified for each layer (i.e., this value) and any overlaps or gaps between the layers. Thus, the section thickness is the value calculated by the program using all of the entries made in this column for each layer of the section.
Modeling Type drop-down list. Use the drop-down list to select the behavior for each layer. Select Membrane to model only in-plane behavior, Plate to model only out-of-plane bending behavior, and Shell to model full shell behavior.
Number Integration Points edit box. Use the default or specify a revised number of integration points in the thickness direction for the layer. The locations are determined by the program using standard Guass-quadrature rules.
Material drop-down list. Use the drop-down list to select the material type for each layer. Each material type will be given a unique color in the display area in the lower left corner of the form.
Material Angle edit box. If appropriate, specify the material angle for the layer definition. The angle is measured counterclockwise from the local 1 axis of the shell object to the local 1 axis of the material.
Material Behavior drop-down list. Choose Directional to independently control behavior for each of the three components. Choosing Coupled will force all three components to be nonlinear, using the Modified Darwin-Pecknold 2-D reinforced concrete material model. For more information about the Modified Darwin-Pecknold model, see the related technical note available from Help > Documentation.
Material Component (S11, S22, and S12) drop-down lists. Choose Linear, Nonlinear, or Inactive from the drop-down list for each component. When any of the components is set to be Linear, the layer will behave linearly in that direction in a nonlinear load case. When any of the components is set to be Nonlinear, the layer will behave nonlinearly in that direction in a nonlinear load case. When any of the components is set to Inactive, the layer will not contribute to the stiffness in that direction in a nonlinear load case.
Note: Unless all three material components are Linear, the Poisson's ratio will be taken as zero in a nonlinear load case, regardless of the value defined in the material property.
Note: Regardless of the selected behavior, all three material components will behave linearly in a linear load case.
Up and Down arrows. When multiple rows of data have been specified, use these buttons to move quickly through the spreadsheet area of the form.
Add, Add Copy, and Delete buttons. Use these buttons to manage the rows of data in the spreadsheet area.
Click the Add button to begin adding data to the spreadsheet.
Highlight a row of data and click the Add Copy button to add a copy of the highlighted row to the spreadsheet.
Highlight a row of data and click the Delete button to remove it from the definition.
Calculated Layer Information area. The Number of Layers, Total Section Thickness, Sum of Layer Overlaps and Sum of Gaps Between Layers values are informational and cannot be edited directly. The program calculates these values based on the entries in other portions of the form.
Cross Section area. A simple drawing of the orientation of the layer(s) relative to the shell reference surface (i.e., the dashed line shown in the display area) is displayed here. As the mouse cursor is moved over the display, its location is displayed as a vertical "Distance" within the layer relative to the shell reference surface.
Highlight Selected Layer check box. When this check box is checked, the layer selected/highlighted in the spreadsheet area will be shown in the Cross Section area with an outline in a darker hue of the Material display color.
Transparency slide bar. The slide bar can be used to increase or decrease the transparency of the layer shown in the Cross Section area.
Vertical Scale slide bar. Use this slide bar to change the scale used to display the cross section of the slab/wall layer.
Order Ascending by Distance button and Order Descending by Distance button. Click these buttons to reorder the rows of data in the spreadsheet area according to the values in the Distance column.
Display the {Slab, Wall} Property Layer Definition Data from as follows:
Click the Define menu > Section Properties > {Slab Sections, Wall Sections} command to display the {Slab, Wall} Properties form.
Then do one of the following to access the {Slab, Wall} Property Data form:
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.
Set the Modeling Type to Layered.
Click the Modify/Show Layered {Slab, Wall} Data button.