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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


next up previous contents
Next: Input deck format Up: Theory Previous: Extrapolation error estimator   Contents
guido dhondt 2014-03-02