cyclic load

[elisapaso]

Hi dear all,
please help me! how do you do a cyclic load?
thanks!

[fmk]

you put the laod in a load pattern and give it a cyclic load pattern .. if a sine or cosine pattern use Trig. otherwise use Path.

[elisapaso]

thanks a lot!

[nparsaeifard]

Dear elisapaso
would you please give the commands of applying static cyclic analysis?
Thank you

[elisapaso]

I have two loads (one at 1/4 and one at 3/4) so i have defined 2 different pattern plain but it's as if don't read the second pattern plain!
These are the commands:

#FORZA CONCENTRATA SX
pattern Plain 2 "Linear" {
load [expr $NK-1] 0. -0.5 0.
load $NK 0. -1. 0.
load [expr $NK+1] 0. -0.5 0. } ;

#FORZA CONCENTRATA DX
pattern Plain 3 "Linear" {
load [expr $NKK-1] 0. -0.5 0.
load $NKK 0. -1. 0.
load [expr $NKK+1] 0. -0.5 0. } ;

for {set i 1} {$i<20} {incr i 1} {

test EnergyIncr 1.e-5 100 ;
integrator DisplacementControl $NK 2 [expr -.02*$i] ;
analyze 40 ;
integrator DisplacementControl $NK 2 [expr .02*$i];
analyze 40 ;
integrator DisplacementControl $NKK 2 [expr -.02*$i] ;
analyze 40 ;
integrator DisplacementControl $NKK 2 [expr .02*$i];
analyze 40 ;
};

There is an error?

[nparsaeifard]

Dear elisapaso
I appreciate your quick response,
I just have some question:
1-what is NKK?
2-where should I put the recorder command to record the displacement at each step?
3-I want to apply a cyclic displacement in which the amplitude of applied displacement is increased at each cycle, if I'm not wrong, I think that your commands apply increasing displacement at each cycle?
Again I thank you very much for your precious guidance and help.

[elisapaso]

1_NK is the first point loaded at 1/4 and NKK is the second point at 3/4
2_I put the commands to record after the definition of these loads but i don't know if is right
3_ Yes i wanted to do this...But i'm not shure it's right. For this reason i have write here
What you think?
Thanks