Regarding Repetitive Monotonic Loading after Riks

[Shahrukh_Islam]

Hi everyone,

I am trying to do a repeated monotonic loading and unloading after Riks analysis. I have done the initial unloading after Riks but am a little bit confused about the repeated loading and unloading. I did the unloading using Static General step post riks by using command prompt. My analysis is displacement controlled. The following is my restart file input. In this case, could you tell me what can I do to do that post Riks?


Script:

*Restart, read, step=1
*Step, name=Unloading-Step, nlgeom=YES
*Static
0.1,1,1e-12,1
*Boundary
Set-16, 2, 2, 0
**
** OUTPUT REQUESTS
**
*Restart, write, overlay, frequency=1
**
** FIELD OUTPUT: F-Output-1
**
*Output, field
*Node Output, variable=PRESELECT
*Element Output, directions=YES, variable=PRESELECT
1, 2, 3, 4, 5
**
** HISTORY OUTPUT: H-Output-1
**
*Output, history, variable=PRESELECT
*End Step

 

[FEA way]

You can define more steps in this restart analysis or use restart procedure multiple times.

 

[Shahrukh_Islam]

Hi there,

So how can I do this repeated loading and unloading easily?

Can I use amplitude? If so, could please kindly tell me how to do it and where should I put the amplitude settings after the unloading step?

Thank you again for your valuable advice.

 

[FEA way]

You only need an amplitude if you want a different time variation of load than ramp - linear increase/decrease. If it’s sufficient then just add/remove loads in subsequent steps. Restart is not necessary if you aren’t changing the analysis procedure and just using general static all the time after the first restart following Riks.