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Re: beam_solid_bar_slip

Posted: Sun Dec 15, 2024 10:48 am
by ssimon
Forgot one important thing: do I need to add a factor when entering seismic waves? In other words, if I enter a ground motion peak of 0.3g, it is not as long as it is consistent with the peak value displayed in the function plot in the timeseries.

Re: beam_solid_bar_slip

Posted: Mon Dec 16, 2024 9:52 am
by STKO Team
would you mind to recommend me a related link? Learning videos or examples on adding ground motion, adding a uniform excitation mode, and ASDAbsorbingBoundary?
https://asdea.eu/software/advanced-e-learning-courses/

I have questions, if the model built with FF and LK is the model I built correct or the deformation is too large so that I can't find out where is the erorr?
I opened the model I noticed some inconsistencies( no mass density in the soil elastic material, not sure if you computed correctly the LK coefficients, missing fixities in the FF columns). Please review carefully your model

By the way, If we use ASDAbsorbingBoundary , is it possible to analyze the soil model with FluidSolidPorousMaterial?
Currently the ASDAbsorbingBoundary work for elastic materials, but we are under beta testing for any other material. In the meantime you can use the manual approach of FF + LK

Forgot one important thing: do I need to add a factor when entering seismic waves? In other words, if I enter a ground motion peak of 0.3g, it is not as long as it is consistent with the peak value displayed in the function plot in the timeseries.
I didn't understand your question. Anyway, you have to be consistent with your unit system

Re: beam_solid_bar_slip

Posted: Wed Dec 18, 2024 12:24 pm
by ssimon
Thank you for taking the time to reply to me! I would like to construct a three-dimensional seismic tunnel-soil model. Is it appropriate for me to only establish the FF columns on both sides? Do you have any better methods or suggestions for the model? I watched the SSI webinar and noticed that the input timeseries is in velocity form, but I am inputting the timeseries in acceleration form. What should I pay attention to regarding the calculation or input of the damping coefficient? :D

Re: beam_solid_bar_slip

Posted: Fri Dec 20, 2024 9:10 am
by STKO Team
Is it appropriate for me to only establish the FF columns on both sides?
Only FF are fine if you do not expect the waves to reflect towards the vertical boundaries, otherwise you can use absorbing boundaries
I watched the SSI webinar and noticed that the input timeseries is in velocity form, but I am inputting the timeseries in acceleration form
If you want absorbing boundaries at the bottom you need the velocity

Re: beam_solid_bar_slip

Posted: Mon Dec 23, 2024 3:04 am
by ssimon
thanks for the reply, I have one more question, which is about the place where the soil and the structure are in contact with each other, in fact it is compressed and not tensioned, my model uses zeroLengthContactASDimplex, but after running it it is found that there is a relative displacement between the structure and the soil, can you teach me how to do it?Figure 1 shows the unit parameters I set

Re: beam_solid_bar_slip

Posted: Thu Jan 02, 2025 5:44 pm
by STKO Team
You set a very soft normal stiffness (Kn = 1).
This contact element uses the penalty approach to enforce the non-penetration constraint. The penalty stiffness should be a high value (in theory infinity, but you can't numerically set an infinite number, so you can choose a stiffness penalty value that is higher than your typical stiffness)

Re: beam_solid_bar_slip

Posted: Tue Jan 07, 2025 6:09 am
by ssimon
Thank you for your reply, but I noticed that there was still a gap , and including the stretching behavior

Re: beam_solid_bar_slip

Posted: Thu Jan 09, 2025 11:43 am
by STKO Team
The gap opening is normal... a contact element only enforces non-penetration, while separation is allowed