there's some problem in eleload command

[wunico]

I use the nonlinearBeamColumn element to build a portal frame, and import an acceleration of ground motion(taft) to this frame,and do the Transient analysis.

I found if I use “eleload command” for adding vertical distributedload to beam .the beam's end section moment-curvature time–history curve is very asymmetric? If I don’t use eleload ,and only add nodal forces to the end points of beam,the curve isn’t asymmetric. Normally,the section moment-curvature time–history curve surrounds the origin .why this beam section’s figure is like this when I add eleload to beam(nonlinear element)? is it a bug of programme ?how can I resolve this problem? In addition,there is not problem when I use beamwithhinges element.

[springtea]

i think it may be a bug,but not sure!
because the manual of eleload said"the forceBeamColumn (nonlinearBeamColumn) element might have problems converging; the current code needs to be redone"
anyone can explain it?