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boundary conditions for hoop stress
Posted 6 set 2012, 03:10 GMT-4 3 Replies
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Hi,
I am new to Comsol structural mechanics and I am trying to solve a very simple problem without any success. I would like to simply solve for the hoop stress on a simple copper ring by applying a pressure on the inside face and without having any fixed constraint. I think I need to apply a weak constraint to keep the model from flying away but I can't seem to apply any boundary condition that gives a suitable answer. So far the only way I have been able to get a semi-suitable solution is to apply a fixed constraint on a single point, but this is not how I want the model to solve. I just want the hoop stress and displacement by a pressure acting on the inside of the ring.
I have attached the model and any help would be greatly appreciate.
I am new to Comsol structural mechanics and I am trying to solve a very simple problem without any success. I would like to simply solve for the hoop stress on a simple copper ring by applying a pressure on the inside face and without having any fixed constraint. I think I need to apply a weak constraint to keep the model from flying away but I can't seem to apply any boundary condition that gives a suitable answer. So far the only way I have been able to get a semi-suitable solution is to apply a fixed constraint on a single point, but this is not how I want the model to solve. I just want the hoop stress and displacement by a pressure acting on the inside of the ring.
I have attached the model and any help would be greatly appreciate.
Attachments:
3 Replies Last Post 7 set 2012, 09:52 GMT-4
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Posted:
1 decade ago
Hi
have you tried to tie your model with a soft "sring funcdation" that should do the job. Or you fix a few points or lines along X,Y,Z respectively with separate restrained displacement nodes, directio nby direction
--
Good luck
Ivar
have you tried to tie your model with a soft "sring funcdation" that should do the job. Or you fix a few points or lines along X,Y,Z respectively with separate restrained displacement nodes, directio nby direction
--
Good luck
Ivar
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Posted:
1 decade ago
Hi,
Thanks for your rapid feedback. I have just tried using your second suggestion of fixing points to move only in certain directions. This seems to work fine for this simple case, but not so easy for a more complex closed shape.
I really think that I need to use the spring fundation, but I am using version 4.2 and I can't seem to find this anywhere??? Is this available in this version. Is it under a different name?
Thanks for your rapid feedback. I have just tried using your second suggestion of fixing points to move only in certain directions. This seems to work fine for this simple case, but not so easy for a more complex closed shape.
I really think that I need to use the spring fundation, but I am using version 4.2 and I can't seem to find this anywhere??? Is this available in this version. Is it under a different name?
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Posted:
1 decade ago
Hi
I'm still on a business travel some 17'000 km from my workstation, so I cannot check, but I though that arrived in v4.2, (perhaps ...a) at least is should be a BC in v4.3
In the worst case you can mimic it by a weak expression with nthe spring force -k*u (resp v,w) where k is the spring force in N/m
--
Good luck
Ivar
I'm still on a business travel some 17'000 km from my workstation, so I cannot check, but I though that arrived in v4.2, (perhaps ...a) at least is should be a BC in v4.3
In the worst case you can mimic it by a weak expression with nthe spring force -k*u (resp v,w) where k is the spring force in N/m
--
Good luck
Ivar