# Metafor

ULiege - Aerospace & Mechanical Engineering

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doc:user:general:unites

# Units

In Metafor, as in most FE codes, units are not explicitly defined. The user must enter input data in a consistent way.

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 $\mbox{kg}$.