Learning Forum

[Kevin.Yanik]

I am trying to determine if I can use the BEM Acoustics Solver/Spectral Element Solver within LSDYNA to study elastic waves in a plate (not necessarily interested in the acoustic field within the fluid medium around it). Appendix W from the manual states that you can use the keyword *Control_Acoustic_Spectral but I do not see that keyword when I search for it in LSPrePost or Workbench LSDYNA through keyword manager (using ver. R13.1 of LSDYNA). I would like to output structural displacement fields in the plate and if possible not output any acoustic pressures in the fluid. Can spectral elements be used for the structural domain (plate)? The matrix equation shows both displacement degrees of freedom and pressure degrees of freedom being solved for, right? If not, can the boundary element method somehow be tailored to study this problem through the use of specific keycards? Please see attached images. I appreciate any feedback in advance. 

Thank you,

Kevin

 

[Reno Genest]

Hello Kevin,

Why do you want to use the BEM acoustic method if you're not interested in acoustics and you only want to calculate elastic waves in the plate? This seems like a purely structural problem. LS-DYNA explicit will calculate the elastic wave in a plate. You can use an elastic material model for the plate (*MAT_001). You will find a simple example here:

https://www.dynaexamples.com/introduction/intro-by-j.-day/elements/rod-i

 

Reno.

[Kevin.Yanik]

Thank you Reno.

[Ushnish Basu]

LS-DYNA does not have spectral elements for elastic waves as yet, so it is not currently practicable to model ultrasonic elastic waves