Engine Keyword Time step control for shell sub-cycling.



Δ T sca Δ T min


Field Contents SI Unit Example
Keyword3 Time step control type.
Nodal mass of the shell elements is increased to maintain the constant time step, Δ T min . Due to this mass increase, momentum is not conserved and the mass increase of the model should be carefully monitored during the computation.

If Keyword3 is not specified, that is, /DT/SHNOD, then the shell elements will use the nodal time step method and is not used.

Δ T sca Scale factor on nodal stability time step for shells.

Default = 0.9

Δ T min Minimum time step.  


  1. Shell sub-cycling is activated by using the Engine file option, /SHSUB.
  2. /DT/SHNOD/CST can be set in the Radioss Engine file, to use an imposed nodal time step for SHELL and SH3N elements sub-cycling. Just like /DT/NODA/CST, mass will be added to maintain Δ T min .
    Δ T sca 2 M Ksh
    is lower than Δ T min
  3. /DT/SHNOD sets a different time step for all shells (SHELL and SH3N) and shells only. Time step parameters of the rest of the model are defined in /DT/NODA. /DT/NODA is required, if /DT/SHNOD is used.