Anonymous
×
Create a new article
Write your page title here:
We currently have 106 articles on MOR Wiki. Type your article name above or click on one of the titles below and start writing!



Windscreen: Difference between revisions

Init Windscreen
 
Added dimension section and fixes
Line 6: Line 6:
==Description==
==Description==
<figure id="fig1">[[File:Windscreen1.gif|490px|thumb|right|Figure 1]]</figure>
<figure id="fig1">[[File:Windscreen1.gif|490px|thumb|right|Figure 1]]</figure>
<figure id="fig1">[[File:Windscreen2.png|490px|thumb|right|Figure 2]]</figure>
<figure id="fig2">[[File:Windscreen2.png|490px|thumb|right|Figure 2]]</figure>


This is an example for a model in the frequency domain of the form
This is an example for a model in the frequency domain of the form
Line 19: Line 19:
The test problem is a structural model of a car windscreen.
The test problem is a structural model of a car windscreen.
This is a 3D problem discretized with <math>7564</math> nodes and <math>5400</math> linear hexahedral elements (3 layers of <math>60 \times 30</math> elements).
This is a 3D problem discretized with <math>7564</math> nodes and <math>5400</math> linear hexahedral elements (3 layers of <math>60 \times 30</math> elements).
The mesh is shown in Figure 1.
The mesh is shown in <xr id="fig1"/>.
The material is glass with the following properties:
The material is glass with the following properties:
The Young modulus is <math>7\times10^{10}\mathrm{N}/\mathrm{m}^2</math>, the density is <math>2490 \mathrm{kg}/\mathrm{m}^3</math>, and the Poisson ratio is <math>0.23</math>. The natural damping is <math>10\%</math>, i.e. <math>\gamma=0.1</math>.
The Young modulus is <math>7\times10^{10}\mathrm{N}/\mathrm{m}^2</math>, the density is <math>2490 \mathrm{kg}/\mathrm{m}^3</math>, and the Poisson ratio is <math>0.23</math>. The natural damping is <math>10\%</math>, i.e. <math>\gamma=0.1</math>.
The structural boundaries are free (free-free boundary conditions).
The structural boundaries are free (free-free boundary conditions).
The windscreen is subjected to a point force applied on a corner.
The windscreen is subjected to a point force applied on a corner.
The goal of the model reduction is the fast evaluation of y.
The goal of the model reduction is the fast evaluation of <math>y</math>.
Model reduction is used as a fast linear solver for a sequence of parametrized linear systems.
Model reduction is used as a fast linear solver for a sequence of parametrized linear systems.


Line 32: Line 32:
\{0.5j,j=1,\ldots,m\}</math> with <math>m=400</math>.
\{0.5j,j=1,\ldots,m\}</math> with <math>m=400</math>.


Figure 1 and Figure 2 show the mesh of the car windscreen and frequency response function.
<xr id="fig1"/> and <xr id="fig2"/> show the mesh of the car windscreen and frequency response function.


==Origin==
==Origin==


This benchmark is part of the '''Oberwolfach Benchmark Collection'''<ref name="korvink2005"/>.
This benchmark is part of the '''Oberwolfach Benchmark Collection'''<ref name="korvink2005"/>; No. 38886.


==Data==
==Data==
Line 45: Line 45:


The archive contains files <tt>windscreen.K</tt>, <tt>windscreen.M</tt> and <tt>windscreen.B</tt> representing <math>Kd</math>, <math>M</math> and <math>f</math> accordingly.
The archive contains files <tt>windscreen.K</tt>, <tt>windscreen.M</tt> and <tt>windscreen.B</tt> representing <math>Kd</math>, <math>M</math> and <math>f</math> accordingly.
==Dimensions==
System structure:
:<math>
\begin{align}
K x - \omega^2 M x &= B \\
y &= B^\intercal x
\end{align}
</math>
System dimensions:
<math>K \in \mathbb{R}^{22692 \times 22692}</math>,
<math>M \in \mathbb{R}^{22692 \times 22692}</math>,
<math>B \in \mathbb{R}^{22692 \times 1}</math>.


==References==
==References==

Revision as of 11:38, 1 March 2018

Note: This page has not been verified by our editors.

Description

Figure 1
Figure 2

This is an example for a model in the frequency domain of the form

Kdxω2Mx=fy=f*x

where f represents a unit point load in one unknown of the state vector. M is a symmetric positive-definite matrix and Kd=(1+iγ)K where K is symmetric positive semi-definite.

The test problem is a structural model of a car windscreen. This is a 3D problem discretized with 7564 nodes and 5400 linear hexahedral elements (3 layers of 60×30 elements). The mesh is shown in xx--CrossReference--dft--fig1--xx. The material is glass with the following properties: The Young modulus is 7×1010N/m2, the density is 2490kg/m3, and the Poisson ratio is 0.23. The natural damping is 10%, i.e. γ=0.1. The structural boundaries are free (free-free boundary conditions). The windscreen is subjected to a point force applied on a corner. The goal of the model reduction is the fast evaluation of y. Model reduction is used as a fast linear solver for a sequence of parametrized linear systems.

The discretized problem has dimension n=22692. The goal is to estimate x(ω) for ω[0.5,200]. In order to generate the plots the frequency range was discretized as {ω1,,ωm}={0.5j,j=1,,m} with m=400.

xx--CrossReference--dft--fig1--xx and xx--CrossReference--dft--fig2--xx show the mesh of the car windscreen and frequency response function.

Origin

This benchmark is part of the Oberwolfach Benchmark Collection[1]; No. 38886.

Data

Download matrices in the Matrix Market format:

The archive contains files windscreen.K, windscreen.M and windscreen.B representing Kd, M and f accordingly.

Dimensions

System structure:

Kxω2Mx=By=Bx

System dimensions:

K22692×22692, M22692×22692, B22692×1.

References

  1. J.G. Korvink, E.B. Rudnyi, Oberwolfach Benchmark Collection, Dimension Reduction of Large-Scale Systems, Lecture Notes in Computational Science and Engineering, vol 45: 311--315, 2005.