| Author | Message | |||
     Wqian (ogle) New member Username: ogle Post Number: 1 Registered: 11-2004 |
Hello. In an axisymmetric problem on thermal elasticity,I find the temperature and stress distrubtion in the right and left part is asymmetirc. The solid with a initial temperature of -40 is exprosured to a heating environment where the heating temperature is "thermload=1000" on its top,the other edges are under the room temperature of 25.Can these be attributed to the discrete inaccuarcy of FEA if the boundary conditons I set is axisym,etric indeed? Thank you very much. List in the attachment is the soruce code By the way,the ultimate goal is to solve the problem by modeling only the right part of the solids.
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| Robert G. Nelson (rgnelson) Moderator Username: rgnelson Post Number: 265 Registered: 06-2003 |
I don't quite understand the trouble here. You say it is an axisymmetric problem, but you have not constructed an axisymmetric geometry. You have an infinite strip. To build an axisymmetric problem, you would use COORDINATES YCYLINDER('R','Z') then delete all the parts at negative R (since these are implied by rotation) and write the equation in terms of R and Z. Also, you should not be using stresses as variables. You already have displacement equations, and the stresses can be computed directly from the displacements. Take a look at some of our thermal stress examples. I tried to run this problem as posted, and the spatial errors immediately climbed to 1e10, so there is something wrong in the initial conditions or boundary conditions. Why don't you start out with the thermal part alone, and see if you can get that to work first? | |||
| Wqian (ogle) New member Username: ogle Post Number: 2 Registered: 11-2004 |
thank you so much,Nelson. After executing some examples,I'm now more clear about the model.I'm sorry I have mistaken symmetric problem for axisymmetric problem. Yes,I have started with the thermal part alone,but still this asymmetric phenomenon still exits in the edge in a symmetric problem. |
