problem in using DisplacementControl Integrator

[teymoorian]

Hi

I have modeled a 3D structure with rigid floors and I want to perform a pushover analysis. the point is that when I use the Loadcontrol Integrator the responses are logical, but when I use DisplacementControl Integrator, the responses is just zero, and it seems that no load is applied. can anyone please tell me what could be the problem? the differences between these methods is here:

DC method:
set Dmax 0.180000
set Dincr [expr int($Dmax/999)]
integrator DisplacementControl 5553 1 $Dincr
analysis Static
set Nsteps 999
set ok [analyze $Nsteps]
puts $ok
puts "Pushover Done . "

LC method:
set Fmax 2433.737582
set Fincr [expr ($Fmax/999.000000)]
integrator LoadControl $Fincr
analysis Static
set Nsteps [expr int($Fmax/$Fincr)] ;# number of pushover analysis steps
set ok [analyze $Nsteps]
puts $ok
puts "Pushover Done . "

[fmk]

have you some actual load in the model .. displacement control tries to find the load factor to apply to reference loads to move structure through displacement you specify, it is not imposed displacement

[teymoorian]

if you mean the load pattern, yes, I have defined "pattern Plain 2 Linear" as load pattern