Incremental Dynamic Analysis

Deby · Post by **Deby** » 20 Jun 2022, 17:04

I'm working on Incremental dynamic analysis. I have trouble while running. If the scale factor is increased, a notification "time 8.2sec iter 32 -> divergent" and then the running stops. what does mean about "time 8.2s iter 32 -> diverg"? What should I do?
Thank you

z.gronti · Post by **z.gronti** » 21 Jun 2022, 14:55

Dear Deby,

You may carry out a search in this form with the 'divergence' term. You will find plenty of resources. Also there is a section in Appendix A in SeismoStruct's User Manual, called 'Tips to Solve Convergence Problems'.

Deby · Post by **Deby** » 22 Jun 2022, 15:09

I was read but haven't found what is the meaning of "iter" in detail. Please explain the meaning of "iter"? Why in the same time can enter different iter?
for example
time 3,7, dt = 0,05 iter : 18 -> converg
time 3,7000 dt = 0,05 iter : 32 -> diverg

Deby · Post by **Deby** » 22 Jun 2022, 15:56

Hi, I have question about it. Please explain this.. How to solve this issue?

Convergence not Achieved
Convergence Message: Diverge
-----------------
Displacement Norm: 0,00010653 / 0,0001
Rotation Norm: 0,02797784 / 0,0001
-----------------

Node 136: Norm of out-of-balance Deformations: 1,00
Node 91: Norm of out-of-balance Deformations: 0,95644739

z.gronti · Post by **z.gronti** » 23 Jun 2022, 11:22

Dear Deby,

Iter means iterations, i.e.it is the number of iterations executed by the program in order to achieve convergence.

Have you tried the steps proposed in SeismoStruct's User Manual for the "Divergence" flag?

Deby · Post by **Deby** » 25 Jun 2022, 02:52

Yes, I have done it and succeeded in scale IDA 0.2-1 with each step 0.2.
But when the scale is increased to 1.2-1.4 with each step 0.2, the structure divergen. what caused it all?

Deby · Post by **Deby** » 25 Jun 2022, 03:04

can i send the model that have done? Please check model..

z.gronti · Post by **z.gronti** » 27 Jun 2022, 09:51

Dear Deby,

If you have tried all the proposed modifications, could it be that your structure cannot stand the applied load?

ydnar_rye · Post by **ydnar_rye** » 09 Sep 2022, 16:14

Hi, I'm working on IDA using Seismostruct. I found a video on how to use IDA in Seismostruct. However, I do not know how to interpret the post-processing values and what are the needed data from Seismostruct for IDA curves.

Here's the sample video I found:
https://www.youtube.com/watch?v=BKvd7eDjEBw

seismosoft · Post by **seismosoft** » 12 Sep 2022, 08:04

Which of the values you do not understand? If you not more specific in your question, we will not be able to provide any help.
In any case make sure that you have read the relevant section in IDA of the Users Manual. Also the paper indicated in the video will be extremely helpful (note however that this is not a video that has been created by Seismosoft).

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