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Greg-Hamel / FEMur

Simple Finite Element Model (FEM) Library
MIT License
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Cauchy Conditions currently resets the nodes, it shouldn't #10

Closed Greg-Hamel closed 7 years ago

Greg-Hamel commented 7 years ago

I made a mistake in the implementation. Current nodes affected by the Cauchy condition are only affected by their neighbouring Cauchy conditions affected nodes and not all nodes like it should be.

Simple fix: Remove the reset part of the update_stiff_load_cauchy() method from in the Mesh2D class.

Greg-Hamel commented 7 years ago

This bug is non-existent. I made a mistake in my understanding of my code.

Greg-Hamel commented 7 years ago

This was actually correct in the first place. The original problem is that nodes are completely reset to zero before cauchy is applied, meaning that they are only dependent on the neighbouring node affected by Cauchy condition. This means that those nodes are not affected by the diffusion inside the element (as if they were simple air particle). For this to function properly, each nodes affected by the cauchy condition should only add the cauchy condition to its stiffness matrix and load vector not overwrite what was currently there.

Greg-Hamel commented 7 years ago

The reset to zero must be removed.

Following this removal, since the addition of Cauchy condition is element-based, the boundary nodes will be given a Cauchy condition more than one time (since more than one element is comprised of the same node). Something has to be done to rectify this problem.

Greg-Hamel commented 7 years ago

This has been corrected in a previous commit.