Use the Hinge Property Data for {Property Name} form to define deformation controlled hinge properties. The options available on the form depend on the type of hinge being defined.
Type area. This area appears on the right portion of the form. The selection made here affects the other options available on the form.
If the Hinge Type is Axial P, Shear V2, or Shear V3, the force-displacement criteria and the acceptance criteria may be input as one of the following:
Force - Displacement. Use this option to specify force versus displacement.
Stress - Strain With the Stress-Strain check box checked, fill in the hinge length in the Hinge Length edit box. The hinge length may be input as an absolute length or a relative length. Check the Relative Length check box to input the hinge length as a relative length. Relative length is a fraction from zero to one of the clear length of the object, i.e., the length of the object minus the length of any end offsets.
When the force-displacement criteria and the acceptance criteria are input as stress versus strain, the program internally converts it to force versus displacement.
For an axial hinge, the force is calculated as stress times the cross-sectional area.
For shear hinges, the force is calculated as stress times the shear area.
For both axial and shear hinges, the displacement is calculated as strain times the hinge length.
If the Hinge Type is Torsion T, Moment 2 or Moment 3, the force-displacement criteria and the acceptance criteria may be input as one of the following:
Moment - Rotation. Use this option to specify moment versus rotation.
Moment - Curvature. With the Moment-Curvature check box checked, fill in the hinge length in the Hinge Length edit box. The hinge length may be input as an absolute length or a relative length. Check the Relative Length check box to input the hinge length as a relative length. Relative length is a fraction from zero to one of the clear length of the element, i.e., the length of the element minus the length of any end offsets.
Hysteresis Type and Parameters. Select the hysteresis type for the curve, and enter the associated parameters as required. See Hysteresis Types for more information.
Spreadsheet area. Fill in the A, B, C, D, and E values (see figure) for the load-deformation table.
Note that the program will multiply the values given in this table by the scale factors specified in the Scaling for {Force and Disp, Moment and Rotation) area. The scale factors usually are chosen to be the yield load (force, stress, or moment) and the yield deformation (displacement, strain, or rotation), although you may use any scaling you wish. For non-symmetric curves, separate scale factors may be given for positive and negative values. In the following, the scale factors are indicated with the subscript SF:
For Axial P hinge properties, when the force-displacement input type is chosen, the force is input as P/PSF and the displacement is input as D/DSF. When the stress-strain input type is chosen, the force (stress) is input as s/sSF and the displacement (strain) is input as e/eSF.
For Shear V2 and Shear V3 hinge properties, when the force-displacement input type is chosen, the force is input as V/VSF and the displacement is input as D/DSF. When the stress-strain input type is chosen, the force (stress) is input as t/tSF and the displacement (strain) is input as e/eSF.
For Torsion T hinge properties, the force is input as T/TSF and the displacement is input as q/qSF.
For Moment M2 and Moment M3 hinge properties, the force is input as M/MSF and the displacement is input as q/qSF.
For P-M2-M3 hinge properties, the force is input as M3/M3SF and the displacement is input as q3/q3SF. You cannot actually specify the moment scale factor M3SF; it is created automatically by the program when the hinge yields. Only the ratios of the moments at B, C, D and E are important, so you can assume any arbitrary value of M3SF when specifying the M3/M3SF values. The program internally creates M2 versus q2 and P versus D curves that are work-equivalent to the given M3/M3SF versus q3/q3SF plot at the time of yielding.
For all of the above, only the plastic deformation can be defined. Elastic deformation is determined by the element containing the hinge. Therefore, only the positive deformations relative to point B and the negative deformations relative to point B’ are important. The load values at B and B’ are important, but not the deformation values (they may be zero).
Load Carrying Capacity Beyond Point E options.
Drops to Zero option. When this option is selected, the load carrying capacity drops to zero at point E.
Is Extrapolated option. When this option is selected, the load carrying capacity is extrapolated at point E (typically extrapolated parallel to line D-E).
Scaling for {Force and Disp, Moment and Rotation) area. Select the scale factors, SF, to be used for the load-deformation curve. Allow the program to compute yield values to be used for this purpose by checking the appropriate Use Yield check box, or uncheck the box and type values in the corresponding SF edit boxes. For non-symmetric curves, separate scale factors may be given for positive and negative values.
Acceptance Criteria area. The Acceptance Criteria IO, LS and CP values are deformations (displacements, strains, or rotations) that have been normalized by the same deformation scale factors used to specify the load deformation curve, and are typically located between points B and C and points B’ and C’ on the curve. They are used to indicate the state of the hinge when viewing the results of the analysis, but they do not affect the behavior of the structure.
Show Acceptance Criteria on Plot check box. Check this check box and ETABS will display the specified acceptance criteria on the model using the colors shown for the individual criterion.
See Also
Access the Hinge Property Data for {Property Name} form as follows:
Click the Define menu > Section Properties > Frame/Wall Nonlinear Hinge command to display the Define Frame/Wall Hinge Properties form. Then do one of the following:
Click the Add New Property button. The Default For Added Hinges form, with Steel, Concrete, and User Define options, will display. Choose an option as the basis for defining the new hinge property. The Hinge Property Data form will display.
Highlight a previously defined property and click the Add Copy of Property or Modify/Show Property button. The Hinge Property Data form will display.
In the Hinge Type area, select the Deformation Controlled or Force Controlled option and then select a specific hinge type from the drop-down list.
Click the Modify/Show Hinge Property button to access the Hinge Property Data for {Property Name} form for the selected Hinge Type. This topic assumes the Deformation Controlled option was selected. Click here for a topic related to the Force Controlled option.
The Hinge Property Data for {Property Name} form also can be displayed by expanding the Properties node and then the Hinge Properties node on the Model tab in the Model Explorer window. Right-click on a hinge and then select the Modify/Show command to display the Hinge Property Data form and click the Modify/Show Hinge Property button.