Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations KootK on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

How to use results from 1st simulation as initial conditions for 2nd eigenfrequency study in COMSOL 1

Status
Not open for further replies.

Duy Binh Pham

Student
Jul 12, 2024
4
Dear All,

I am trying to define the dispersion curves of a periodic unit cell in COMSOL Multiphysics with prescribed displacements. I am using two separate studies:
- Study 1: Stationary, with prescribed displacements on the four edges of the unit cell.
- Study 2: Eigenfrequency.
I intend to use the results of Study 1 as initial conditions for Study 2.
I also conducted a different eigenfrequency study of the same unit cell, and the dispersion curves from Study 2 and this separate study are similar. This suggests that the results from Study 1 may not have been used as initial conditions for Study 2.
The following figures illustrate my setup. Could I be missing any setup errors?
Thank you in advance

Displacement on left edge:
left_displacement_ya4hzs.png

Displacement on right edge:
right_displacement_boalfd.png

Displacement on top edge:
top_displacement_u3fp0y.png

Displacement on bottom edge:
bottom_displacement_lrk29l.png

Study 1 (Stationary) setup: I turn off Floquet-periodic BCs in study 1)
study_1_set_up_by2zqs.png

Deformed shape of the unit cell from Study 1:
study_1_result_uybmsx.png

Floquet-periodic BCs along x direction:
periodicity_x_direction_fkqjhi.png

Floquet-periodic BCs along z direction:
periodicity_z_direction_ixbw3r.png

Study 2(Eigenfrequency) setup:
study_2_setup_wrfkcf.png

Study 2 setup (Turn off "Solved for" of study 1):
study_2_set_up_2_gtkidh.png

Dispersion curves from Study 2:
Eigenfrequency_results_Study_2_rrygca.png

An eigenmode from Study 2:
an_eigenmode_of_Study_2_dxo92b.png

A different eigenfrequency study(without prescribed displacements) set up:
single_eigenfrequency_setup_zujaie.png

Dispersion curves from the different eigenfrequency study:
Eigenfrequency_results_single_study_fhv5s5.png

An eigenmode the different eigenfrequency study:
an_eigenmode_of_single_eigenfrequency_study_jwmgwi.png
 
Replies continue below

Recommended for you

Well, I worked in FEA and modal analysis for 15 years, and can honestly say I haven't got the faintest idea what you are on about.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376
 
Hi GregLocock,

Thank you for your comment. I am a new newcomer. I have updated my problem, please consider it.

Best wishes,
Binh
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor