Skip to content

Commit 42a47da

Browse files
mleoni-pfjorgensdjuliusghrossbm1MPenaR
committed
Update elasticity_scaling.md (#242)
* Improve workflow handling (#118) * Create common action for all workflows and split them into multiple files * Dokken/update fspace and wmtgs (#127) * fix runs-on * Minor improvements in linearelasticity.md (#124) * Fix various things on release branch * Try adding trame * Revert fundamentals * Membrane code * More updates due to autoformatting * Lagrange -> CG back conversion * Change to github image --------- Co-authored-by: Julius Herb <43179176+juliusgh@users.noreply.github.com> * Update petsc arches * Fix bounding boxes and more (#135) * Start fixing code for nightly build * rerun all files * Try fixing subdomains * Fix meshio * PETSc python API update (#137) * Resolve #136 * Fixes related to: FEniCS/dolfinx#2703 * Update changelog * Make sure all notebooks run. Change to pathlib in some examples * Api changes related to: FEniCS/dolfinx#2763 (#142) * Bump version numbers * Bump version numbers (#149) * Fix petsc arch * Prepare v0.7.1 (#154) * Merge branch 'main' into release and bump versions * Delete obsolete file * Temporary shift path in nightly test * Make sure there are no warnigns in build * Tabulation * Updates compatible with nightly branch of DOLFINx (#156) * Replace VectorElement and FiniteElement with `basix.ufl.element`. Replace `dolfinx.fem.FunctionSpace` with `dolfinx.fem.functionspace` * More updates * And more * Last vector element updates * Bump pyvista and dolfinx to v0.7.2 (#159) * Bump pyvista and dolfinx to v0.7.2 * remove -r * Add further pyvista deps * Bump versions * Update petsc solver and pc links. Resolves #143 (#160) * Fix typo and issue Issue on page /fem.html #122 (#161) * Compute entity-cell connectivity before calling locate_dofs_topological. Remove soon to be deprecated pyvista syntax for updating time dependent fields. Fix range->np.arange conversion * Update backend in workflow * Fix broken link (#140) + http:// to https:// (#162) * Run book build prior to parallel run * Add back write frame * Fix wrong link * Fix typo in changelog * Merge main into release (#189) * Merge main into release * Apply suggestions from code review * Various fixes when reading through the diff * Further fixes * add missing checkout (#191) * add missing checkout * Add test docker on release PR and release (only push on tag * Remove unused import * Update text to resolve #194 (#195) * Dokken/update nonlin options (#203) * Update options for non-linear solver to sensible choice, ref #200 * Update docker path * Update python file as well * Update config ptr (#207) * Pressure correction equation fix (#196) * Update fundamentals.md (#199) on line 110, updated a typesetting error in equation (3) * Change from vector to petsc_vec (#206) * dolfinx.fem.Form changed to dolfinx.fem.form (#213) * Update compiler_parameters.ipynb In the text it was mentioned that `dolfinx.fem.Form` was used to compile the form, instead of `dolfinx.fem.form`. Not matching the code cell. * jupytext sync * Form -> form in both py and ipynb and LinearProblem -> fem.petsc.LinearProblem * Update book_stable.yml * Update test_stable.yml * Fix python path in test * Fix CI (#227) * Bump docker/build-push-action from 5 to 6 (#221) Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 5 to 6. - [Release notes](https://github.com/docker/build-push-action/releases) - [Commits](docker/build-push-action@v5...v6) --- updated-dependencies: - dependency-name: docker/build-push-action dependency-type: direct:production update-type: version-update:semver-major ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> * Bump actions/configure-pages from 4 to 5 (#222) Bumps [actions/configure-pages](https://github.com/actions/configure-pages) from 4 to 5. - [Release notes](https://github.com/actions/configure-pages/releases) - [Commits](actions/configure-pages@v4...v5) --- updated-dependencies: - dependency-name: actions/configure-pages dependency-type: direct:production update-type: version-update:semver-major ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> * Update book_stable.yml (#225) * Update book_stable.yml * Update test_stable.yml * resolve #224 (#226) * Update test_stable.yml --------- Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> * Update test_stable.yml (#235) * Add libgl flag to ci (#238) * Update elasticity_scaling.md --------- Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: Jørgen Schartum Dokken <dokken92@gmail.com> Co-authored-by: Jørgen S. Dokken <dokken@simula.no> Co-authored-by: Julius Herb <43179176+juliusgh@users.noreply.github.com> Co-authored-by: rossbm1 <120818149+rossbm1@users.noreply.github.com> Co-authored-by: Manuel Pena <mpena991@gmail.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
1 parent 260fa82 commit 42a47da

File tree

1 file changed

+2
-2
lines changed

1 file changed

+2
-2
lines changed

chapter2/elasticity_scaling.md

+2-2
Original file line numberDiff line numberDiff line change
@@ -18,6 +18,6 @@ where $\beta = 1+\frac{\lambda}{\mu}$ is a dimensionless elasticity parameter an
1818
```
1919
is a dimensionless variable reflecting the ratio of the load $\rho g$ and the shear stress term $\mu \nabla^2u \sim \mu \frac{U}{L^2}$ in the PDE.
2020

21-
One option for the scaling is to chose $U$ such that $\gamma$ is of unit size ($U=\frac{\rho g L^2}{\mu}$). However, in elasticity, this leads to displacements of the size of the geometry. This can be achieved by choosing $U$ equal to the maximum deflection of a clamped beam, for which there actually exists a formula: $U=\frac{3}{2} \rho g L^2\frac{\delta^2}{E}$ where $\delta=\frac{L}{W}$ is a parameter reflecting how slender the beam is, and $E$ is the modulus of elasticity. Thus the dimensionless parameter $\delta$ is very important in the problem (as expected $\delta\gg 1$ is what gives beam theory!). Taking $E$ to be of the same order as $\mu$, which in this case and for many materials, we realize that $\gamma \sim \delta^{-2}$ is an appropriate choice. Experimenting with the code to find a displacement that "looks right" in the plots of the deformed geometry, points to $\gamma=0.4\delta^{-2}$ as our final choice of $\gamma$.
21+
One option for the scaling is to choose $U$ such that $\gamma$ is of unit size ($U=\frac{\rho g L^2}{\mu}$). However, in elasticity, this leads to displacements of the size of the geometry. This can be achieved by choosing $U$ equal to the maximum deflection of a clamped beam, for which there actually exists a formula: $U=\frac{3}{2} \rho g L^2\frac{\delta^2}{E}$ where $\delta=\frac{L}{W}$ is a parameter reflecting how slender the beam is, and $E$ is the modulus of elasticity. Thus the dimensionless parameter $\delta$ is very important in the problem (as expected $\delta\gg 1$ is what gives beam theory!). Taking $E$ to be of the same order as $\mu$, which in this case and for many materials, we realize that $\gamma \sim \delta^{-2}$ is an appropriate choice. Experimenting with the code to find a displacement that "looks right" in the plots of the deformed geometry, points to $\gamma=0.4\delta^{-2}$ as our final choice of $\gamma$.
2222

23-
The simulation code implements the problem with dimensions and physical parameters $\lambda, \mu, \rho, g, L$ and $W$. However, we can easily reuse this code for a scaled problem: Just set $\mu=\rho=L=1$, $W$ as $W/L(\delta^{-1})$, $g=\gamma$ and $\lambda=\beta$.
23+
The simulation code implements the problem with dimensions and physical parameters $\lambda, \mu, \rho, g, L$ and $W$. However, we can easily reuse this code for a scaled problem: Just set $\mu=\rho=L=1$, $W$ as $W/L(\delta^{-1})$, $g=\gamma$ and $\lambda=\beta$.

0 commit comments

Comments
 (0)