Output variables

Output is provided with the commands *NODE FILE and *EL FILE in the .frd file (ASCII), with the commands *NODE OUTPUT and *ELEMENT OUTPUT in the .frd file (binary) and with the commands *NODE PRINT and *EL PRINT in the .dat file (ASCII). Binary .frd files are much shorter and can be faster read by CalculiX GraphiX. Nodal variables (selected by the *NODE FILE, *NODE OUTPUT and *NODE PRINT keywords) are always stored at the nodes. Element variables (selected by the *EL FILE, *ELEMENT OUTPUT and *ELEMENT PRINT keywords) are stored at the integration points in the .dat file and at the nodes in the .frd file. Notice that element variables are more accurate at the integration points. The values at the nodes are extrapolated values and consequently less accurate. For example, the von Mises stress and the equivalent plastic strain at the integration points have to lie on the stress-strain curve defined by the user underneath the *PLASTIC card, the extrapolated values at the nodes do not have to.

In fluid networks interpolation is used to calculate the nodal values at nodes in which they are not defined. Indeed, due to the structure of a network element the total temperature, the static temperature and the total pressure are determined at the end nodes, whereas the mass flow is calculated at the middle nodes. Therefore, to guarantee a continuous representation in the .frd file the values of the total temperature, the static temperature and the total pressure at the middle nodes are interpolated from their end node values and the end node values of the mass flow are determined from the neighboring mid-node values. This is not done for .dat file values (missing values are in that case zero).

A major different between the FILE and PRINT requests is that the PRINT requests HAVE TO be accompanied by a set name. Consequently, the output can be limited to a few nodes or elements. The output in the .frd file can but does not have to be restricted to subsets. If no node set is selected by using the NSET parameter (both for nodal and element values, since output in the .frd file is always at the nodes) output is for the complete model.

The following output variables are available:

Table: (continued)
Table 17: List of output variables.

variable	meaning	type	.frd file	.dat file
U	displacement	nodal	x	x
PU	magnitude and phase	nodal	x
	of displacement
MAXU	worst displacement	nodal	x
	orthogonal to a given vector
	in cyclic symmetric
	frequency calculations
NT	structural temperature	nodal	x	x
	total temperature in a network
PNT	magnitude and phase	nodal	x
	of temperature
TT	total temperature in a gas network	nodal	x
TS	static temperature in a network	nodal	x	x
TTF	total temperature in a 3D fluid	nodal	x	x
TSF	static temperature in a 3D fluid	nodal	x	x
RF	reaction force	nodal	x	x
RFL	reaction flux	nodal	x	x
PT	total pressure in a gas network	nodal	x
PS	static pressure in a liquid network	nodal	x	x
PN	network pressure (generic term for any of the above)	nodal		x
PTF	total pressure in a 3D fluid	nodal	x	x
PSF	static pressure in a 3D fluid	nodal	x	x
CP	pressure coefficient in a compressible 3D fluid	nodal	x	x
DEPT	fluid depth in a channel network	nodal	x
HCRI	critical depth in a channel network	nodal	x
MF	mass flow in a network	nodal	x	x
V	velocity of a structure	nodal	x	x
VF	velocity in a 3D fluid	nodal	x	x
MACH	Mach number in a compressible 3D fluid	nodal	x	x
S	Cauchy stress (structure)	element	x	x
SF	total stress (3D fluid)	element	x	x
SVF	viscous stress (3D fluid)	element	x
ZZS	Zienkiewicz-Zhu stress	element	x
PHS	magnitude and phase	element	x
	of stress
MAXS	worst principal stress	element	x
	in cyclic symmetric
	frequency calculations
HFL	heat flux in a structure	element	x	x
HFLF	heat flux in a 3D fluid	element	x	x
E	Lagrange strain	element	x	x
MAXE	worst principal strain	element	x
	in cyclic symmetric
	frequency calculations
PEEQ	equivalent plastic strain	element	x	x
ENER	internal energy	element	x	x
SDV	internal variables	element	x	x
ELSE	internal energy	whole		x
		element
ELKE	kinetic energy	whole		x
		element
EVOL	volume	whole		x
		element
DRAG	stress on surface	surface		x
FLUX	flux through surface	surface		x