This option can be used only in conjunction with the FRAME SECTION option. It describes the axial force in a frame element as a function of the axial plastic displacement.
There are no parameters associated with this option.
Data lines to define the variation of axial yield force with plastic displacement
First line
Axial yield force.
Plastic axial displacement.
Repeat this data line as often as necessary to define the relationship between the axial force and the axial plastic displacement. At least three pairs of data are required.