Hi,I have some questions about simulating a Box of wood in air with abaqus.
Reading the documentation I saw that this can be done using several techniques.I must take care about the size of the elements. The 3D elements minimum size can be calculate using the formula give in the doc and using at least 6 node per wavelenght.
For the size of the accoustic elements I use the formula from the doc and I use element size of minimum 1/8 of the wavelenght.
To simulate a wood box in the air i can do :
1/. Enclose the box in a sphere of air. Box use 3D solid elements, air use Accoustic elements. For creating the coupling between thebox and the air sphere, I can use a TIE constraint. I must take care about the distance of the radius of the air sphere, wich is minimum 1/3 of the wavelenght. I must also use aboundary contition SIMPEDANCE=NOREFLECTING at the surface of the air-sphere.
2./ I can use infinite elements by creating a air sphere with a little radius and and inifites elements on the surface of the air sphere. My questions are :
- Is the TIE constaint between my solid box and the air sphere with acoustic element is requier also in this case ?  ;
- How can I calculate the minimum radius of the air spehere wich contain acoustic element in this case ?
- For using infinit elements, canyou explain me how to do this under CAE ? Do i must create a new part sphere just behind the air sphere (with a translation of fo example 0.000001) and apply the inifit element on this new part ? Or can I shell the surface of my air sphere wich contain already acoustic elements ? If yes, how ? (I'e tried to mesh a surface by declarating a surface but it seems impossible...)
3./ It seems that the infinites elements can be use directly on the surface of the box, with no air sphere at all. Is it true ?
Thanks you very much for your help. Regards.
Reading the documentation I saw that this can be done using several techniques.I must take care about the size of the elements. The 3D elements minimum size can be calculate using the formula give in the doc and using at least 6 node per wavelenght.
For the size of the accoustic elements I use the formula from the doc and I use element size of minimum 1/8 of the wavelenght.
To simulate a wood box in the air i can do :
1/. Enclose the box in a sphere of air. Box use 3D solid elements, air use Accoustic elements. For creating the coupling between thebox and the air sphere, I can use a TIE constraint. I must take care about the distance of the radius of the air sphere, wich is minimum 1/3 of the wavelenght. I must also use aboundary contition SIMPEDANCE=NOREFLECTING at the surface of the air-sphere.
2./ I can use infinite elements by creating a air sphere with a little radius and and inifites elements on the surface of the air sphere. My questions are :
- Is the TIE constaint between my solid box and the air sphere with acoustic element is requier also in this case ?  ;
- How can I calculate the minimum radius of the air spehere wich contain acoustic element in this case ?
- For using infinit elements, canyou explain me how to do this under CAE ? Do i must create a new part sphere just behind the air sphere (with a translation of fo example 0.000001) and apply the inifit element on this new part ? Or can I shell the surface of my air sphere wich contain already acoustic elements ? If yes, how ? (I'e tried to mesh a surface by declarating a surface but it seems impossible...)
3./ It seems that the infinites elements can be use directly on the surface of the box, with no air sphere at all. Is it true ?
Thanks you very much for your help. Regards.