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Yield function & plasticity

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Hi,

im trying to use Comsol Strutural Mechanics Module to simulate some geotechnical problems. I created a rectangle with roller boundaries on the left, right and bottom boundary. The upper boundary is a load in the -y-direction. The expected stress state does not reach a plastic state.
Using perfectly plastic with von Mises yield function, or Drucker Prager yield function, the solver doesn't find convergence.
Moving the upper right point 0.0001m against the y-direction, the sovler finds convergence after a few seconds.

Where is the problem?


2 Replies Last Post Jan 9, 2010, 3:35 p.m. EST
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Posted: 1 decade ago Jan 9, 2010, 3:35 p.m. EST
You have parametric solver with a parameter "para". I did not see "para" in any of your equations.
Is your solution supposed to be in plastic region?



Hi,

im trying to use Comsol Strutural Mechanics Module to simulate some geotechnical problems. I created a rectangle with roller boundaries on the left, right and bottom boundary. The upper boundary is a load in the -y-direction. The expected stress state does not reach a plastic state.
Using perfectly plastic with von Mises yield function, or Drucker Prager yield function, the solver doesn't find convergence.
Moving the upper right point 0.0001m against the y-direction, the sovler finds convergence after a few seconds.

Where is the problem?


You have parametric solver with a parameter "para". I did not see "para" in any of your equations. Is your solution supposed to be in plastic region? [QUOTE] Hi, im trying to use Comsol Strutural Mechanics Module to simulate some geotechnical problems. I created a rectangle with roller boundaries on the left, right and bottom boundary. The upper boundary is a load in the -y-direction. The expected stress state does not reach a plastic state. Using perfectly plastic with von Mises yield function, or Drucker Prager yield function, the solver doesn't find convergence. Moving the upper right point 0.0001m against the y-direction, the sovler finds convergence after a few seconds. Where is the problem? [/QUOTE]

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Jan 9, 2010, 3:35 p.m. EST
You have parametric solver with a parameter "para". I did not see "para" in any of your equations.
Is your solution supposed to be in plastic region?



Hi,

im trying to use Comsol Strutural Mechanics Module to simulate some geotechnical problems. I created a rectangle with roller boundaries on the left, right and bottom boundary. The upper boundary is a load in the -y-direction. The expected stress state does not reach a plastic state.
Using perfectly plastic with von Mises yield function, or Drucker Prager yield function, the solver doesn't find convergence.
Moving the upper right point 0.0001m against the y-direction, the sovler finds convergence after a few seconds.

Where is the problem?


You have parametric solver with a parameter "para". I did not see "para" in any of your equations. Is your solution supposed to be in plastic region? [QUOTE] Hi, im trying to use Comsol Strutural Mechanics Module to simulate some geotechnical problems. I created a rectangle with roller boundaries on the left, right and bottom boundary. The upper boundary is a load in the -y-direction. The expected stress state does not reach a plastic state. Using perfectly plastic with von Mises yield function, or Drucker Prager yield function, the solver doesn't find convergence. Moving the upper right point 0.0001m against the y-direction, the sovler finds convergence after a few seconds. Where is the problem? [/QUOTE]

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