acspain
Mechanical
- Feb 23, 2011
- 48
Hello Everyone,
We are trying to solve a couple of problems (with FEA) that occasional occur with welded metal bellows. One is called squirm (a type of column instability caused primarily by ID pressure) and flip (where a convolution of the bellows changes orientation during loading (pressure, displacement)). To model these phenomena, I think we should start with a 180 degree sweep of the geometry and because of the thin material (.002 - .010 inch thick) making up the diaphragms you end up with a large model very quickly with lots of contact pairs. ANSYS is currently struggling to solve the squirm analysis. Yes we can run a linear eigenvalue buckling analysis for squirm but this precludes loading the part as it would exist in application which will affect the pressure at which the part squirms.
I have a decade plus of experience using Abaqus but that was a while ago and need to check my memory. If memory serves, we could put difficult to solve models into explicit and run either a full dynamic run or quasi-static run and get an answer regardless (within reason and of course checking energies) of the size of model and amount of contact. ANSYS meanwhile seems to be choking on the amount of contact and size of model.
2 questions:
1. Is my memory correct that Abaqus Explicit would be able to solve this problem? Given enough time/cpus.
2. How should we be tackling this problem in ANSYS?
Sorry for the lack of detail, but looking for a high level approach to the problem due to my lack of experience with ANSYS.
Thank you for your help.
We are trying to solve a couple of problems (with FEA) that occasional occur with welded metal bellows. One is called squirm (a type of column instability caused primarily by ID pressure) and flip (where a convolution of the bellows changes orientation during loading (pressure, displacement)). To model these phenomena, I think we should start with a 180 degree sweep of the geometry and because of the thin material (.002 - .010 inch thick) making up the diaphragms you end up with a large model very quickly with lots of contact pairs. ANSYS is currently struggling to solve the squirm analysis. Yes we can run a linear eigenvalue buckling analysis for squirm but this precludes loading the part as it would exist in application which will affect the pressure at which the part squirms.
I have a decade plus of experience using Abaqus but that was a while ago and need to check my memory. If memory serves, we could put difficult to solve models into explicit and run either a full dynamic run or quasi-static run and get an answer regardless (within reason and of course checking energies) of the size of model and amount of contact. ANSYS meanwhile seems to be choking on the amount of contact and size of model.
2 questions:
1. Is my memory correct that Abaqus Explicit would be able to solve this problem? Given enough time/cpus.
2. How should we be tackling this problem in ANSYS?
Sorry for the lack of detail, but looking for a high level approach to the problem due to my lack of experience with ANSYS.
Thank you for your help.