PARADISCYL:Cylinder-bug

Discontinuities in stress  : usage of cell

ILL RYU

May 1, 2010

ParaDiS uses cells to compute stress. Now, if we use more than 3 cells, there are discontinuities near the boundary of cells. Here, 3 kinds of models are tested to see the discontinuities: Using 3 cells without FMM, Using 8 cells without FMM, Using 8 cells with FMM.

Model geometries

In the model, square dislocation loop is located at the center of the simulation domain as following figure.

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  [cylinder_square]

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Blue line : 3 cells without FMM
Red line: 8 cells without FMM
Green line: 8 cells with FMM

Infinite stress

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Image stress stress

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Total stress

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Conclusion

As we can see, if we use more that 3 cells for the stress calculation, the solutions are getting unstable.