Linear & Non-Linear.
Posted: 03 Nov 2011, 15:56
Hi Everyone,
I am new to Elmer and even though I have read the guides available at the elmer pages, I couldn't understand how to really use them.
Now i am trying to analize a simple estructure both with a linear procedure and a non-linear one. The ElmerSolver starts without problems, but after 20 iterations it says that the system didn't converge for both of them. I am afraid that i am defining something wrong since the structure is not very complicated and the node number isn't extremely high. There is a very thin part but the mesh overthere is thick enough to get a rough solution at least.
The lines written at the .sif file are:
file 1: Linear Analysis
File2: Non-Linear
Are the Linear and Non-Linear Parameters well defined? Are the Procedure variable and the Equation Variable correctly defined?
I got the lines from the tutorials and as the parameters suit me too, i left them unmodified.
Thanks in Advance
Supituki
I am new to Elmer and even though I have read the guides available at the elmer pages, I couldn't understand how to really use them.
Now i am trying to analize a simple estructure both with a linear procedure and a non-linear one. The ElmerSolver starts without problems, but after 20 iterations it says that the system didn't converge for both of them. I am afraid that i am defining something wrong since the structure is not very complicated and the node number isn't extremely high. There is a very thin part but the mesh overthere is thick enough to get a rough solution at least.
The lines written at the .sif file are:
file 1: Linear Analysis
Code: Select all
Solver 1
Equation = Linear elasticity
Procedure = "ElasticSolve" "ElasticSolver"
Variable = -dofs 3 Displacement
Exec Solver = Always
Stabilize = True
Bubbles = False
Lumped Mass Matrix = False
Optimize Bandwidth = True
Steady State Convergence Tolerance = 1.0e-5
Nonlinear System Convergence Tolerance = 1.0e-8
Nonlinear System Max Iterations = 20
Nonlinear System Newton After Iterations = 3
Nonlinear System Newton After Tolerance = 1.0e-3
Nonlinear System Relaxation Factor = 1
Linear System Solver = Iterative
Linear System Iterative Method = BiCGStab
Linear System Max Iterations = 500
Linear System Convergence Tolerance = 1.0e-8
Linear System Preconditioning = ILU0
Linear System ILUT Tolerance = 1.0e-3
Linear System Abort Not Converged = False
Linear System Residual Output = 1
Linear System Precondition Recompute = 1
End
Equation 1
Name = "Equation 1"
Active Solvers(1) = 1
EndCode: Select all
Solver 1
Equation = Nonlinear elasticity
Procedure = "StressSolve" "StressSolver"
Variable = -dofs 3 Displacement
Exec Solver = Always
Stabilize = True
Bubbles = False
Lumped Mass Matrix = False
Optimize Bandwidth = True
Steady State Convergence Tolerance = 1.0e-5
Nonlinear System Convergence Tolerance = 1.0e-8
Nonlinear System Max Iterations = 20
Nonlinear System Newton After Iterations = 3
Nonlinear System Newton After Tolerance = 1.0e-3
Nonlinear System Relaxation Factor = 1
Linear System Solver = Iterative
Linear System Iterative Method = BiCGStab
Linear System Max Iterations = 500
Linear System Convergence Tolerance = 1.0e-8
Linear System Preconditioning = ILU0
Linear System ILUT Tolerance = 1.0e-3
Linear System Abort Not Converged = False
Linear System Residual Output = 1
Linear System Precondition Recompute = 1
End
Equation 1
Name = "Equation 1"
Active Solvers(1) = 1
EndI got the lines from the tutorials and as the parameters suit me too, i left them unmodified.
Thanks in Advance
Supituki