# Metafor

ULiege - Aerospace & Mechanical Engineering

### Site Tools

doc:user:general:locks

﻿

# Fields at Nodes

## Definition

Nodal fields (such as the displacement, the velocity, the temperature, etc.) are defined thanks to a combination of two “codes”: a Nature and a Variant.

field = Field1D(Nature, Variant)

Here is a list of some Nature identifiers :

Nature meaning
TX X-coordinate
TY Y-coordinate
TZ Z-coordinate
TO temperature
TM time

and the most basic Variant ones

Variant meaning
RE relative
AB absolute
GF1 force #1 - External Forces (reaction & contact)
GF2 force #2 - Internal Forces
GF3 force #3 - Inertial Forces
GV first order derivative – velocity
GA second order derivative – acceleration

Examples:

The meaning of a given Field1D is deduced from the previous tables by combining the two components:

Field meaning
Field1D(TX,RE) “X-coordinate”, “relative” = displacement along X
Field1D(TX,AB) “X-coordinate”, “absolute” = initial position along X
Field1D(TX,GF1) “X-coordinate”, “force #1” = external load along X
Field1D(TY,GA) “Y-coordinate”, “acceleration” = acceleration along Y

## Common Nodal Fields used in Metafor

Field1D Meaning in Metafor
Field1D(TX,AB), Field1D(TY,AB), Field1D(TZ,AB) initial positions ($x$, $y$ and $z$)
Field1D(TX,RE), Field1D(TY,RE), Field1D(TZ,RE) displacements ($x$, $y$ and $z$)
Field1D(TO,AB) initial temperature
Field1D(TO,RE) temperature variation
Field1D(TX,GV), Field1D(TY,GV), Field1D(TZ,GV) velocities ($v_x$, $v_z$ and $v_z$)
Field1D(TX,GA), Field1D(TY,GA), Field1D(TZ,GA) accelerations ($a_x$, $a_y$, $a_z$)
Field1D(TM,RE) time
Field1D(TX,GF1), Field1D(TY,GF1), Field1D(TZ,GF1) mechanical external forces / contact forces
Field1D(TX,GF2), Field1D(TY,GF2), Field1D(TZ,GF2) mechanical internal forces
Field1D(TX,GF3), Field1D(TY,GF3), Field1D(TZ,GF3) inertia forces
Field1D(TO,GF1) thermal external forces
Field1D(TO,GF2) thermal external forces 