To model nonlinear frame behavior, frame hinges must be used. The nonlinear material behavior is only used to develop the moment rotation or other response curves for the hinges.

Key Steps to Setup a Model With Hinges

• Define hinge properties using "Define > Section Properties > Hinge Properties" menu command.
• Assign the hinges to the frame elements in the model by using Assign > Frame > Hinges menu command.
• Create a nonlinear load case and run the analysis.
• Use "Display > Show Hinge Results" menu command to plot the deformation of the hinges vs. the applied loads, such as plastic rotation of the hinge vs. moment.

See Also

• CSI Analysis Reference Manual, chapter "Frame Hinge Properties"
• Verification Example 1-026 (Frame - Moment and Shear Hinges), available from "Help > Documentation > Analysis Verification > Frames > 1-026 Moment and Shear Hinges".
• Ashraf Habibullah, Stephen Pyle: Practical Three Dimensional Nonlinear Static Pushover Analysis - this technical paper describes the use of hinges for pushover analysis; it is available from http://www.csiberkeley.com/support/technical-papers