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
…	…