Use the Nonlinear Material Data form to specify the nonlinear material property data to be used if property nonlinearity is considered during analysis.
Material Name display box. The name of the material property to which the nonlinear property data applies appears in this display box.
Material Type display box. The material type to which the nonlinear property data applies appears in this display box. The type selected determines the parameters required on the form and is set on the preceding Material Property Data form.
Hysteresis Type drop-down list. Select the hysteresis type for the curve, and enter the associated parameters as required. See Hysteresis Types for more information.
Drucker-Prager Parameters and the Friction Angle and Dilatational Angle edit boxes. When available (i.e., concrete material type), use the defaults or type values in degrees in the edit boxes.
Stress-
Strain Curve Definition Options. Choose to define the stress-strain curve parametrically or by specifying values directly.
Parametric option and drop-down list and Convert to User Defined button.
Parametric Strain Data area. Use the suggested default values or enter revised values in the edit boxes in this area to specify the Strain at the Unconfined Compressive Strength and the Ultimate Unconfined Strain Capacity.
Show Stress-Strain Plot button. Click this button to display the Material Stress-Strain Curve Plot form.
Click the Convert to User Defined button to tailor parametrically defined nonlinear material data. Clicking the button displays a spreadsheet in the lower half of the form (similar to the User Defined option); use the form to modify the data to meet specific needs.
User Defined option. When this option is selected, specify the number of points to be used to define the plot in the Number of Points in Stress-Strain Curve edit box. The number specified in this edit box determines the number of rows of data required in the spreadsheet in the User Stress-Strain Curve Data area. Use the default or enter revised values in the cells in the Strain and Stress columns
Order Rows button. After entering data in this spreadsheet, click this button to reorder the rows in ascending order, which is necessary for the data to plot correctly.
Show Plot button. Click this button to display the Material Stress-Strain Curve Plot form.
After the nonlinear data has been specified as part of the material property definition, the definition can be assigned to a selected frame(s) or a slab, deck, or wall object(s).
Access the Nonlinear Material Data form as follows:
Click the Define menu > Materials command to access the Define Materials form.
Then do one of the following to access the Material Property Data form:
Click the Add New Material button to access the Add New Material Property form; specify a new property definition.
Highlight an existing definition and click the Add Copy of Material or Modify/Show Material button.
Click the Nonlinear Material Data button to access the Nonlinear Material Data form.