Nodal Fields

Definition

Fields are codes used to refer to nodal values. These codes must be known to use Metafor, and are divided into two entities, a Nature and a Variant.

field = Field(Nature, Variant)

Here is a list of some Nature identifiers :

`Nature`	meaning
`TX`	X-coordinate (default)
`TY`	Y-coordinate
`TZ`	Z-coordinate
`TO`	temperature
`TM`	time

and the most basic Variant ones

`Variant`	meaning
`RE`	relative (default)
`AB`	absolute
`GF1`	force #1
`GF2`	force #2
`GF3`	force #3
`GV`	first order derivative – velocity
`GA`	second order derivative – acceleration

Examples:

The meaning of a given Field 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

Fields used in Metafor

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