Output Messages

The following is part of a printout (in step 2 of the Engine output file _0001.out) when the keyword /IMPL/PRINT/NONLIN/n is used in the Engine file (_0001.rad):

CYCLE    TIME   TIME-STEP  ELEMENT  ERROR  I-ENERGY   K-ENERGY T  K-ENERGY R  EXT-W
-------
   2   2.380      0.4802     SHELL   0.0%   5.117      0.000           0.000  5.117
    --SUPPLEMENTARY CONTACT STIFFNESS MATRIX IS CREATED--
     WITH DIM. : ND   =     141 NZ  =    1050 NB_MAX =      15
    NL_ITERATION=    0   INITIAL RESIDUAL NORM= 0.5913E+01 0.4613E+04 0.1600E+05
    --STIFFNESS MATRIX IS REFORMED --
    --SUPPLEMENTARY CONTACT STIFFNESS MATRIX IS CREATED--
     WITH DIM. : ND   =     150 NZ  =    1059 NB_MAX =      15
    NL_ITERATION=    1  RELATIVE RESIDUAL NORM= 0.1000E+01 0.8593E-01 0.5005E-01
    --SUPPLEMENTARY CONTACT STIFFNESS MATRIX IS CREATED--
     WITH DIM. : ND   =     156 NZ  =    1101 NB_MAX =      15
 
  CONVERGED WITH 2 ITERATIONS, |du|/|u|,|r|/|r0|,|dE|/|E|= 0.5915 0.4747E-01 0.1166

Each iteration contains a printout of the normalized (L2 Norm) initial values (iteration zero) or relative one of displacement, force residual and energy. So |du|/|u| is relative residual in displacement, |r|/|r0| is relative residual in force and |dE|/|E| is relative residual in energy.

Stiffness Matrix Setup

At the start of every computation, the following message is printed:

   *--------- STIFFNESS MATRIX SETUP ---------*
 SYMBOLIC DIM : ND =  164202 NZ =   6047160 NB_MAX =      96
 FINAL    DIM : ND =  154605 NZ =   5652417 NB_MAX =      96

Where,

ND: Dimension of the stiffness matrix (number of DOFs)
NZ: Number of non-zero values of the strict triangular matrix (only ND+NZ values are stored due to the symmetry of matrix)
NB_MAX: Maximum number of connected nodes in the model

Radioss eliminates all dependent nodes (this process is called 'condensation') before resolution, and so the SYMBOLIC and FINAL dimensions correspond respectively to the matrix dimension before and after condensation.

If contact is taken into account, the stiffness matrix of penalty spring is stored independently and information on this is printed (if /IMPL/PRINT/NONLIN/n is defined) once contacts are detected:

--SUPPLEMENTARY CONTACT STIFFNESS MATRIX IS CREATED--
     WITH DIM. : ND   =      42 NZ  =      42 NB_MAX =      16

Note: Only information of the final (after condensation) matrix information is printed out.

In the Radioss SPMD version, the sub-matrix of the main stiffness matrix stored on each machine is printed; and for the supplementary contact matrix, only the total final one is printed.

CPU information

If the keyword /MON/ON is defined in the Radioss Engine input file (_0001.rad), some detailed information regarding CPU processing time information for the implicit scheme is printed in the .out file:

#PROC  [K]SETUP [M]SETUP IMPL.SOLV IMPL.TOTAL
   1   .2484E+01 .1528E+02 .6742E+02 .8520E+02
 #PROC  CONT.SORT  CONT.  F ELEMENT  MAT KIN.COND.  INTEGR.     I/O     TASK0  ASSEMB.    RESOL
   1   .0000E+00 .0000E+00   .1875     .3125E-01     .0000  .0000E+00  .2188 .2188  .0000   .8561E+02
----------
 ELAPSED TIME :     89.32 s

Where,

$[K]$: Main stiffness matrix
$[M]$: Pre-conditioning matrix (if iterative solver is used)
IMPL.SOLV: For the resolution of {x}=[K]-1{b}

The numerical values represent time.

Output Solving for each Iteration (/IMPL/SOLV and /IMPL/NONLIN/SOLVINFO)

Output global solve information at each solving iteration. This command creates three additional files:

Filename_implicit.info: For largest residuals (force and moment), largest displacement and rotation increments and largest corrections at each iteration and each increment.
Filename_implicit.hist: Contains all data for plotting purposes in Altair Simulation.
Filename_implicit.tpl: A tpl script for plotting in Altair Simulation the data from .hist file.