Mechanical APDL Basic Analysis Guide

Load Type Applied in Load Step 1 Introduced in Later Load Steps

Body

Temperatures Ramped from TUNIF[ 2 ] Ramped from previous TUNIF[ 3 ]

Ramped from previous

BFUNIF[ 3 ]

Others Ramped from BFUNIF[ 5 ]

Inertia [ 1 ] Ramped from zero Ramped from zero

1. For OMEGA loads, OMEGA is ramped linearly; the resulting force vary quadratically over the load step.


2. The TUNIF command specifies a uniform temperature at all nodes. Since TUNIF (or BFUNIF,TEMP) is
   step-applied in the first iteration, you should use BF, ALL,TEMP, Value to ramp on a uniform temperature
   load.


3. In this case, the TUNIF or BFUNIF value from the previous load step is used, not the current value.


4. Temperature-dependent film coefficients are always applied at the value dictated by their temperature
   function, regardless of the KBC setting.


5. The BFUNIF command is a generic form of TUNIF, meant to specify a uniform body load at all nodes.

2.6.1.6. Other General Options.

You can also specify the following general options:

• The reference temperature for thermal strain calculations, which defaults to zero degrees. Specify
  this temperature as follows:
  Command(s):TREF
  GUI: Main Menu> Preprocessor> Loads> Load Step Opts> Other> Reference Temp
  Main Menu> Preprocessor> Loads> Define Loads> Settings> Reference Temp
  Main Menu> Solution> Load Step Opts> Other> Reference Temp
  Main Menu> Solution> Define Loads> Settings> Reference Temp


• Whether a new factorized matrix is required for each solution (that is, each equilibrium iteration).
  You can do this only in a static (steady-state) or transient analysis, using one of these methods:
  Command(s):KUSE
  GUI: Main Menu> Preprocessor> Loads> Load Step Opts> Other> Reuse LN22 Matrix
  Main Menu> Solution> Load Step Opts> Other> Reuse LN22 Matrix

By default, the program decides whether a new matrix is required, based on such things as

changes in DOF constraints, temperature-dependent material properties, and the Newton-

Raphson option. If KUSE is set to 1, the program reuses the previous factorized matrix. This setting

cannot be used during a multiframe restart. The command KUSE,-1 forces the factorized matrix

to be reformulated at every equilibrium iteration. Analyses rarely require this; you use it mainly

for debugging purposes.

To generat e and keep the Jobname.LN22 file, issue the command EQSLV,SPARSE,,,,KEEP

command.

• A mode number (the number of harmonic waves around the circumference) and whether the har-
  monic component is symmetric or antisymmetric about the global X axis. When you use axisymmetric
  harmonic elements (axisymmetric elements with nonaxisymmetric loading), the loads are specified

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