Have to use fiber elements to get P-Delta for pushover?

[bjturner]

I've written a simple program to track the force versus displacement relationship for a cantilevered column under displacement-controlled lateral loading, and I've discretized the column into "nonlinearbeamcolumn" elements. When I add an axial load, the column is not picking up additional moments due to P-Delta effects like I expected. What is the simplest way to model nonlinear section behavior while capturing P-Delta moments? Do I have to use fiber elements?

Thanks,
Ben

[Panos]

Above all, you 'll have to change the geometric Transformation to PDelta http://opensees.berkeley.edu/wiki/index ... sformation (I'm guessing you're using Linear).