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Structural model and Complex Velocity
Posted Nov 23, 2009, 7:46 a.m. EST 4 Replies
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Hello All,
Maybe this is a fundamental question but, I am a little bit confused to see complex velocity results in my structural model which doesn't have any loss / damping or visco-elastic material?
Can somebody please explain me how this happens with v_t_smsh variable or similar variables with "_t_"?
Thanks,
Onur
Maybe this is a fundamental question but, I am a little bit confused to see complex velocity results in my structural model which doesn't have any loss / damping or visco-elastic material?
Can somebody please explain me how this happens with v_t_smsh variable or similar variables with "_t_"?
Thanks,
Onur
4 Replies Last Post Feb 1, 2010, 12:33 p.m. EST
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Posted:
2 decades ago
Hi
Is it possible to be lightly more expliit about what you are doing: application mode, type of modelling, BC's ... it would help to better understand your case.
I agree, normally complex values are only linked to damping in structural
Ivar
Is it possible to be lightly more expliit about what you are doing: application mode, type of modelling, BC's ... it would help to better understand your case.
I agree, normally complex values are only linked to damping in structural
Ivar
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Posted:
2 decades ago
Hi,
First of all, thank you for your interest in my problem.
To simplify my problem, I have created a 3D Structural Frequency Analysis model, with a conical shell geometry. I have applied a force (real) from the circumfrence where the radius is small and the direction is paralel to the symmetry axis of the cone. The other edge of the cone was left free. I picked a direct solver and solved the problem. After the solution is complete without any warnings, I am clicking on the Boundary Integration and I am selecting the cone surface to integrate. The result is a complex number. On the other hand, the displacement or the acceleration results are real.
Any ideas?
/Onur
First of all, thank you for your interest in my problem.
To simplify my problem, I have created a 3D Structural Frequency Analysis model, with a conical shell geometry. I have applied a force (real) from the circumfrence where the radius is small and the direction is paralel to the symmetry axis of the cone. The other edge of the cone was left free. I picked a direct solver and solved the problem. After the solution is complete without any warnings, I am clicking on the Boundary Integration and I am selecting the cone surface to integrate. The result is a complex number. On the other hand, the displacement or the acceleration results are real.
Any ideas?
/Onur
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Posted:
1 decade ago
Hi
if you are doing a frequency analysis it's normal, as the velocity is 90° out of phase from the acceleration, it comes from the j*omega representation from my understanding, just as displacement and acceleration has 180° dephasing (but both are real without any damping)
Ivar
if you are doing a frequency analysis it's normal, as the velocity is 90° out of phase from the acceleration, it comes from the j*omega representation from my understanding, just as displacement and acceleration has 180° dephasing (but both are real without any damping)
Ivar
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Posted:
1 decade ago
Hi Ivar,
I have the following problem if you can help me:
I am trying to build a model of one object that moving with different speeds and come in contact with other object (see attachment), what i want to know How can i model the object to move with different speed and how can figure out the Vonmises stress during the simulation
Thanx
Ali
I have the following problem if you can help me:
I am trying to build a model of one object that moving with different speeds and come in contact with other object (see attachment), what i want to know How can i model the object to move with different speed and how can figure out the Vonmises stress during the simulation
Thanx
Ali
Attachments: