No Results from simulation
Answers
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Have you had a look at my model file??
I just wish to know if it would be possible to read Sound Pressure Level at a random point after the strike??0 -
Hi Abhi,
Yes, few questions:
Where do you want to get the pressure level?
What is the load on the ball?.. You can provide a spcd but the value of the same is required!!?
The location and all is required.
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Initially I was planning to have initial velocity on the ball that hits the rigid wall...
But because you suggested, we changed that to velocity on the wall... But still I would prefer it otherwise
The sound pressure level can be found at any location close the point of hitting...
For infinite acoustic analysis, I will go through the theory once...
I was wondering if you could send me the example file...
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I just got an idea, how about creating an acoustic cavity around the ball and eliminating air component around itself. Applying air material and properties to it, without any seat component..
Still I would require information on setting up the load step for the same.
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Hi Abhi,
Since impact is not a way in FRF, you can apply enforced displacement or velocity on the ball to calculate responses.
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As per the Altair Help, RADSND card defines grids (microphone locations) where sound levels will be calculated and the locations of the corresponding source (vibrating panels) grids.
The RADSND card is however not compsatible with analysis except Frequency response or Transient Analysis...
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Altair Forum User said:
As per the Altair Help, RADSND card defines grids (microphone locations) where sound levels will be calculated and the locations of the corresponding source (vibrating panels) grids.
The RADSND card is however not compsatible with analysis except Frequency response or Transient Analysis...
@Prakash Pagadala, did you find any help for Loadsteps... or if even Optistruct is compatible enough to carry out Radiated Sound Analysis??
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I have shared an example file for analysis with infinite elements.
Please go through the example and model accordinly. Make sure the outer elements are of Infinite element type.
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@Prakash Pagadala,
I got your file and I checked it also,I see that 1. The material for sphere is non existing.
2. There is a property named: Undefined_1, which is linked to component: outer_sphere_interface, for which the card image and material cards are empty.
3. The output is undefined, I think the SPL, SPOWER and SINTENS output form will suit our requirement.
4. The SPC and SPCD loadcollectors are also empty, if you can explain me their purpose, maybe I can define them and run the simulation.
5. I think there is no material defined for the sphere itself, the material is defined for the sphere shell and the outer covering materials.. But that might not be a problem anyways, I can define that...0 -
Altair Forum User said:
1. The material for sphere is non existing.
core material is AL and for all fluid mesh MAT10 is used
Altair Forum User said:2. There is a property named: Undefined_1, which is linked to component: outer_sphere_interface, for which the card image and material cards are empty.
Looks like there is some problem with the file. I will share the .hm file instead
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@Prakash Pagadala
There are two load collectors, SPC and SPCD; as far as I understood, SPC is containing Velocity;
But SPCD, I cannot understand....Also, on running the file you sent, I see no results, the ball stands at its own place
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Hi Abhi,
SPC is constraints and SPCD is used for velocity.
Please refer to RLOAD card.
Altair Forum User said:Also, on running the file you sent, I see no results, the ball stands at its own place
I used minimal velocity. Increase the velocity and check the results.
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I increased the ball velocity still it does not move, rather it vibrates in its own location,
I think that you have introduced a Frequency excitation load too as far as I understand. (Because we do not need an excitation, we need a simple phenomenon where the ball hits and produces sound..)
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HI Abhi,
I need to check if there is an option for impact at all.
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Did you find any solution??
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I am waiting for your answer,
Is Optistruct capable enough to perform my required analysis??
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One way is to get the impact load (convert to pressure load) and use the same as load in acoustic analysis
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Altair Forum User said:
One way is to get the impact load (convert to pressure load) and use the same as load in acoustic analysis
So for this I think we need to remove the ball and convert it's impacting status to values and generating a force of equivalent magnitude on the plate and then generate the frequency response analysis??
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Altair Forum User said:
Hi,
I have a query regarding an acoustic analysis using Optistruct.
I am doing 'Transmission loss' analysis of a duct system. For a start- i am trying with simple expansion chamber problem. I have defined acoustic source (ACSRCE) at inlet and non-reflecting boundary condition at inlet and outlet end of pipe (Using CAABSF element with PAABSF property entry of impedance equal to = “Rho*C”). In frequency response analysis, i have extracted input point (9001) and output point (9002) pressure values.
<?xml version="1.0" encoding="UTF-8"?>
<?xml version="1.0" encoding="UTF-8"?>
I am using Optistruct_14.0.220_windows solver. Following are the results for Transmission Loss (TL) – { TL = 20 * log10(Pin / Pout) } -
<?xml version="1.0" encoding="UTF-8"?>
I have also calculated transmission loss using analytical approach. Transmission loss in a simple expansion chamber is analytically calculated (worldly proven formula/graph) as shown – <?xml version="1.0" encoding="UTF-8"?>
<?xml version="1.0" encoding="UTF-8"?>
The transmission loss Vs Frequency graph from analytical approach is not matching with FEM solution. FEM solution is showing increasing values with extra trough at 144.0 Hz.
Does anybody have come across similar problem? Is anything wrong in model definition?
I heard of “Annular duct modes boundary condition” (used by software’s like LMS Virtual lab, etc). Are such boundary conditions are also available in Optistruct?
I tries converting the impact of ball into numerical values and assigned equivalent force on the plate, it generates some favorable results, which I shall confirm more.
If you can help me understand solution for the above quoted query, then maybe I can figure out a solution to my problem.
I need to understand assigning, ACSRCE, CAABSF and PAABSF0 -
I've sent you my model and the querry via FTP link,
Please look into it and please help me for any possibility.
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Did you find something?
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Hi @Abhi05
There are few issues with the model.
Please take the reference of the model I shared (use RANDSD, etc...) and try again,
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Altair Forum User said:
Please take the reference of the model I shared (use RANDSD, etc...) and try again,
I did not receive any model file..
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The ball remaining stationery in your model has not changed but in my new model, I have changed a few things, however, there is one slight error that still exists.
I have shared it via FTP, could you please check?
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Hi,
OK, thanks I will update you soon.
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