Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.
Infinite terrain ground motion
Posted Mar 9, 2017, 3:39 a.m. EST Acoustics & Vibrations, Structural Mechanics Version 5.2a 1 Reply
Please login with a confirmed email address before reporting spam
Hello,
I'm trying to model fluid-structure interaction for dams during earthquakes using the solid mechanics interface for the dam and terrain and the acoustic interface for the reservoir, and I'm foucsed on estimating radiation damping of outgoing waves in the terrain.
Now, if I use PML or Low Reflection Boundary Condition to simulate the infiinite ground I must exploit the relativity principle and apply a body load to the structure and terrain, opposite to the seismic acceleration input, since I cannot prescribe an ancceleration to the external ground boundary anymore, since its already present the PML or LRBC.
The problem is that by doing so the acoustic coupling effect changes.
I tested the coupling firstly by removing PML/LRBC and studying the same model, once with the acceleration prescribed at the boundary and once with the fixed constraint at the boundary and an acceleration body load.
Without the acoustic domain the results are perfectly identical, while with the introduction of the acoustics part they do not match anymore.
Can you suggest a solution for that? The aim is to estimate the radiation of waves in the infinite terrain while including fluid-structure interaction.
Thanks
I'm trying to model fluid-structure interaction for dams during earthquakes using the solid mechanics interface for the dam and terrain and the acoustic interface for the reservoir, and I'm foucsed on estimating radiation damping of outgoing waves in the terrain.
Now, if I use PML or Low Reflection Boundary Condition to simulate the infiinite ground I must exploit the relativity principle and apply a body load to the structure and terrain, opposite to the seismic acceleration input, since I cannot prescribe an ancceleration to the external ground boundary anymore, since its already present the PML or LRBC.
The problem is that by doing so the acoustic coupling effect changes.
I tested the coupling firstly by removing PML/LRBC and studying the same model, once with the acceleration prescribed at the boundary and once with the fixed constraint at the boundary and an acceleration body load.
Without the acoustic domain the results are perfectly identical, while with the introduction of the acoustics part they do not match anymore.
Can you suggest a solution for that? The aim is to estimate the radiation of waves in the infinite terrain while including fluid-structure interaction.
Thanks
1 Reply Last Post Mar 9, 2017, 3:50 a.m. EST
Please login with a confirmed email address before reporting spam
Posted:
7 years ago
Here is the model:
There is Structural mechanics in imp1, r1,r2,r3,r4,sq1,sq2 and acoustics in b1 and r5.
The solid mechanics PML is in r2,r3,r4,sq1,sq2 while the acoustic PML is in r5.
Alternatively the NRBC is imposed on the external sides of r1 while disabling r2,r3,r4,sq1 and sq2.
The acceleration boundary condition is imposed in imp1 and r1,r2,r3,r4,sq1 and sq2 as a body force or on the sides and bottom of r1 as a boundary condition.
A zero pressure is imposed at the top of b1 and r5.
The study is in the frequency domain.
There is Structural mechanics in imp1, r1,r2,r3,r4,sq1,sq2 and acoustics in b1 and r5.
The solid mechanics PML is in r2,r3,r4,sq1,sq2 while the acoustic PML is in r5.
Alternatively the NRBC is imposed on the external sides of r1 while disabling r2,r3,r4,sq1 and sq2.
The acceleration boundary condition is imposed in imp1 and r1,r2,r3,r4,sq1 and sq2 as a body force or on the sides and bottom of r1 as a boundary condition.
A zero pressure is imposed at the top of b1 and r5.
The study is in the frequency domain.
Attachments: