Wood Physics & Wood Materials
ETHZ / D-BAUG / FS23
ETHZ / D-BAUG / FS23
Kartei Details
Karten | 102 |
---|---|
Sprache | English |
Kategorie | Naturkunde |
Stufe | Universität |
Erstellt / Aktualisiert | 17.07.2023 / 10.08.2023 |
Lizenzierung | Keine Angabe |
Weblink |
https://card2brain.ch/box/20230717_wood_physics_wood_materials
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Einbinden |
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Raman Imaging
Purpose: investigate cell wall polymers with high spatial resolution, while retaining the structure
Sample requirements: for surface scans the surface has to be as flat as possible (microtome cuts or polishing)
Spectral imaging: for every pixel a spectrum covering the entire wave number range is obtained
Fast imaging: intensity only at one specific wave number
Applications:
Visualization of the wood composition (cellulose and lignin)
Information about the orientation of the cellulose microfibrils
Visualization of the chemical modification area
Bulk Densities
in \(\left[ kg/m^3 \right]\)
spruce
470
douglas fir
530
larch
500 - 560
pine
350 - 850
maple
620 - 750
oak
600 -900
birch (european)
670
ash (european)
710
beech
700 - 900
ebony
1100 - 1300
balsa
110 - 140
Relative Moduli of Elasticity
\(E_T < E_R << E_L\)
softwood:
1 : 1.7 : 20
hardwood
1 : 1.7 : 13
Moduli of Elasticity
Impact factors
- moisture content
- microfibril angle
in \(\left[ N/mm^2 \right]\)
\(E_L -- E_T -- E_R\)
Spruce
10'000 -- 450 -- 800
Pine
11'000 -- 500 -- 1000
Oak
13'000 -- 920 -- 1580
Azobe/Bongossi
17'000 -- 2060 -- 3230
Extended Hooke's law for orthotropic materials
\(\begin{bmatrix}\varepsilon_1 \\ \varepsilon_2 \\ \varepsilon_3 \\\gamma_{23} \\ \gamma_{13} \\ \gamma_{12} \\\end{bmatrix}=\begin{bmatrix}\frac{1}{E_1} & -\frac{\mu_{21}}{E_2} & -\frac{\mu_{31}}{E_3} & 0 & 0 & 0 \\-\frac{\mu_{12}}{E_1} & \frac{1}{E_2} & -\frac{\mu_{32}}{E_3} & 0 & 0 & 0 \\-\frac{\mu_{13}}{E_1} & -\frac{\mu_{23}}{E_2} & \frac{1}{E_3} & 0 & 0 & 0 \\0 & 0 & 0 & \frac{1}{G_{23}} & 0 & 0 \\0 & 0 & 0 & 0 & \frac{1}{G_{13}} & 0 \\0 & 0 & 0 & 0 & 0 & \frac{1}{G_{12}} \\\end{bmatrix}\cdot\begin{bmatrix}\sigma_1 \\ \sigma_2 \\ \sigma_3 \\\tau_{23} \\ \tau_{13} \\ \tau_{12} \\\end{bmatrix}\)
3 E-Moduli
3 Shear Moduli
6 Poisson's ratios