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simulating moving piston
Posted 1 apr 2013, 18:52 GMT-4 Structural Mechanics 4 Replies
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There are 4 components in my model; blood, blood vessel, brain tissue, and piston
Blood and blood vessel are surrounded by brain tissue and piston crushes down brain tissue with 1mm depth.
When I used different software, I used prescribed displacement and divided one time step into several calculations so that I was able to see the movement of the piston during one time step and visualize stress and strain at each calculation.
But I assume that I cannot do it with comsol in the same manner.
Is there any ideas that I can let piston move 1mm and visualize strains while it is moving ?
Any help will be appreciative.
Jay
Blood and blood vessel are surrounded by brain tissue and piston crushes down brain tissue with 1mm depth.
When I used different software, I used prescribed displacement and divided one time step into several calculations so that I was able to see the movement of the piston during one time step and visualize stress and strain at each calculation.
But I assume that I cannot do it with comsol in the same manner.
Is there any ideas that I can let piston move 1mm and visualize strains while it is moving ?
Any help will be appreciative.
Jay
4 Replies Last Post 19 set 2013, 12:26 GMT-4
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Posted:
1 decade ago
Hi
but isn't this a typical FSI model, with contact, or easier with local pressure applied ?
Then you have the fluid flow, the solid and the ALE
--
Good luck
Ivar
but isn't this a typical FSI model, with contact, or easier with local pressure applied ?
Then you have the fluid flow, the solid and the ALE
--
Good luck
Ivar
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Posted:
1 decade ago
Ivar
I am a beginner of comsol and wondering if I need to use prescribed displacement for my model.
Jay
I am a beginner of comsol and wondering if I need to use prescribed displacement for my model.
Jay
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Posted:
1 decade ago
Hi
if you are a beginner I would advice to start "simple" take one physics at the tme and make smaller separate models first, then once you master them try to combine them.
Also Constact is a tricky physics, often needing some more in depth tweaking tht you need to learn by doing, so if you can star witha prescribed displacement (and derive forces as reaction forces in the post treatment = Results section) it's easier. Another way is to impose boundary forces and measure the average displacement
--
Good luck
Ivar
if you are a beginner I would advice to start "simple" take one physics at the tme and make smaller separate models first, then once you master them try to combine them.
Also Constact is a tricky physics, often needing some more in depth tweaking tht you need to learn by doing, so if you can star witha prescribed displacement (and derive forces as reaction forces in the post treatment = Results section) it's easier. Another way is to impose boundary forces and measure the average displacement
--
Good luck
Ivar
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Posted:
1 decade ago
Ivar,
I am trying to simulate a moving piston in a cylinder. I started with simple geometries (2D rectangular). I tried two methods and both failed.
1. FSI module: for solid, using Prescribed Velocity (0.2*wv1(t)). A error massage "failed to evaluate spf.U ..." pops up soon after computation. (filed attached, moving piston.mph)
2. Moving wall: with laminar flow module, specify one wall as "Moving wall with y velocity as 0.2*wv1(t). But the computational results didn't show the wall moments. (filed attached, moving piston try2.mph)
I will grateful if you cold give me some advices on how to make the piston moves. Thanks for your help.
JInxiang
I am trying to simulate a moving piston in a cylinder. I started with simple geometries (2D rectangular). I tried two methods and both failed.
1. FSI module: for solid, using Prescribed Velocity (0.2*wv1(t)). A error massage "failed to evaluate spf.U ..." pops up soon after computation. (filed attached, moving piston.mph)
2. Moving wall: with laminar flow module, specify one wall as "Moving wall with y velocity as 0.2*wv1(t). But the computational results didn't show the wall moments. (filed attached, moving piston try2.mph)
I will grateful if you cold give me some advices on how to make the piston moves. Thanks for your help.
JInxiang
Attachments: