Differences

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--- doc:user:general:unites [2014/08/06 16:54] – joris
+++ doc:user:general:unites [2015/01/07 10:44] – boman
@@ Line 1: / Line 1: @@
 ====== Units ======
+In Metafor, as in most FE codes, units are not explicitly defined. The user must enter input data in a consistent way.
-The unit system must be consistent:
+^	   ^  SI                        ^  SI (mm)              ^
+|Length    |  $\mbox{m}$	        |  $\mbox{mm}$	        |
+|Force     |  $\mbox{N}$	        |  $\mbox{N}$	        |
+|Mass      |  $\mbox{kg}$	        |  $\mbox{tonne}$ 	|
+|Time      |  $\mbox{s}$	        |  $\mbox{s}$	        |
+|Stress    |  $\mbox{Pa } \left ( \mbox{N}/\mbox{m}^2 \right ) $  |  $\mbox{MPa } \left ( \mbox{N}/\mbox{mm}^2 \right ) $	|
+|Energy    |  $\mbox{J}$	        |  $\mbox{mJ } \left ( 10^{–3} \mbox{J} \right ) $  |
+|Density   |  $\mbox{kg/m³}$       |  $\mbox{tonne} / \mbox{mm}^3$	|
+For example, if the geometry (point coordinates) is expressed in meters and the boundary conditions (loads) in Newton, the Young's Modulus appearing in the material definition must be expressed in $\mbox{N/m}^2$. Likewise, a geometry in meters and a Young's Modulus in $\mbox{kg/m}^2$ lead to forces in $\mbox{kg}$.
-^	        ^  SI                   ^  SI (mm)              ^
-|Lenght        |  $\mbox{m}$	        |  $\mbox{mm}$	        |
-|Force         |  $\mbox{N}$	        |  $\mbox{N}$	        |
-|Mass          |  $\mbox{kg}$	        |  $\mbox{tonne}$ 	|
-|Time          |  $\mbox{s}$	        |  $\mbox{s}$	        |
-|Stress        |  $\mbox{Pa } \left ( \mbox{N}/\mbox{m}^2 \right ) $  |  $\mbox{MPa } \left ( \mbox{N}/\mbox{mm}^2 \right ) $	|
-|Energy        |  $\mbox{J}$	        |  $\mbox{mJ } \left ( 10^{–3} \mbox{J} \right ) $  |
-|Density       |  $\mbox{kg/m³}$       |  $\mbox{tonne} / \mbox{mm}^3$	|
-Units are not explicitly defined, the user must enter its data in a consistent way. For example, if the geometry is expressed in meters and the boundary conditions in Newton, Young Modulus must be in $\mbox{N/m}^2$. Likewise, a geometry in meters and a Young Modulus in $\mbox{kg/m}^2$ lead to forces in $\mbox{kg}$.