Post by account_disabled on Feb 1, 2018 11:23:41 GMT
Hello,
I've worked with some of the tutorials of Elmer, and have a 2 questions. One more philosophical, one more nuts and bolts. I'm a professional engineer, with previous FEA experience solving elasticity problems with integrated solutions (ProEngineer / Mechanica), so though I am not entirely new to FEA, I humbly ask for patience if I ask the obvious (rabak, I believe you're quite busy!)...
1. Philosophy: Having now worked with Elmer, and Lisa, I now see there are different philosopies for setting up problems. Consider a cantilever beam, running in the x-direction, loaded in the y-direction. In Elmer, the "glued" end of the beam is fixed by applying 0 displacements to the entire end-face. This is intuitive, and similar to what I'm used to. LISA however, (a linear FEM software) requires assignment of loads and constraints on a node-by-node basis. Therefore, one tries to account for poisson effects at the "glued" end of the beam by (for instance) fixing x-displacement on *all* nodes of the glued-face, then fixing the y-displacement on the *bottom edge* nodes of the glued-face, and then fixing z-displacement on a *single node at the bottom corner* of the glued face. This is also intuitive in it's own way.
So here's the 'obvious' question #1: How does elmer (much like Pro/Mechanica) account for the theoretical poisson-related distortions of the glued-end-face?
2. Convergence, solver, preconditioning, etc: I recall that in one of the tutorials, the instruction is give to change one of the parameters for the solver, to avoid convergence problems.
So question #2: Are there tips (or references I should study / learn) for setting the parameters for the solver?
Thanks
I didn't find the right solution from the internet.
References:
www.elmerfem.org/forum/viewtopic.php?f=7&t=583
SaaS Promotion
I've worked with some of the tutorials of Elmer, and have a 2 questions. One more philosophical, one more nuts and bolts. I'm a professional engineer, with previous FEA experience solving elasticity problems with integrated solutions (ProEngineer / Mechanica), so though I am not entirely new to FEA, I humbly ask for patience if I ask the obvious (rabak, I believe you're quite busy!)...
1. Philosophy: Having now worked with Elmer, and Lisa, I now see there are different philosopies for setting up problems. Consider a cantilever beam, running in the x-direction, loaded in the y-direction. In Elmer, the "glued" end of the beam is fixed by applying 0 displacements to the entire end-face. This is intuitive, and similar to what I'm used to. LISA however, (a linear FEM software) requires assignment of loads and constraints on a node-by-node basis. Therefore, one tries to account for poisson effects at the "glued" end of the beam by (for instance) fixing x-displacement on *all* nodes of the glued-face, then fixing the y-displacement on the *bottom edge* nodes of the glued-face, and then fixing z-displacement on a *single node at the bottom corner* of the glued face. This is also intuitive in it's own way.
So here's the 'obvious' question #1: How does elmer (much like Pro/Mechanica) account for the theoretical poisson-related distortions of the glued-end-face?
2. Convergence, solver, preconditioning, etc: I recall that in one of the tutorials, the instruction is give to change one of the parameters for the solver, to avoid convergence problems.
So question #2: Are there tips (or references I should study / learn) for setting the parameters for the solver?
Thanks
I didn't find the right solution from the internet.
References:
www.elmerfem.org/forum/viewtopic.php?f=7&t=583
SaaS Promotion