/DT/INTER/Keyword3/Iflag
Engine Keyword Interface time step control.
Format
/DT/INTER/Keyword3/IflagIflag
$\text{\Delta}{T}_{sca}$ $\text{\Delta}{T}_{\mathrm{min}}$
If using /DT/INTER/AMS/1, insert the next line.
Tol_AMS
Definitions
Data  Description  SI Unit Example 

Keyword3  Time step control type.
1:
If Keyword3 is not specified, i.e. /DT/INTER, then $\text{\Delta}{T}_{\mathrm{min}}$ is not used and $\text{\Delta}{T}_{sca}$ is used for TYPE7 contacts only. 

Iflag  Number of additional
(optional) cards. Only used when
Keyword3=AMS.


$\text{\Delta}{T}_{sca}$  Scale factor on critical
time step for interface. Default = 0.9 

$\text{\Delta}{T}_{\mathrm{min}}$  Minimum time step.  
Tol_AMS  Tolerance for AMS
convergence  only used for
/DT/INTER/AMS/1. Default = 10^{3} 
Comments
 For all
Keyword3 options, the time step control will be activated
when the time step of the node controlling the time step of the simulation
becomes less than:
$\frac{\text{\Delta}{T}_{\mathrm{min}}}{\text{\Delta}{T}_{sca}}$
 All Keyword3 options are only applicable for TYPE7, TYPE10, TYPE11, and TYPE19 interfaces.
 Keyword3= STOP also applies to TYPE21 interfaces.
 Both /DT/INTER/CST and /DT/INTER/AMS can be used at the same time as /DT/INTER/DEL or /DT/INTER/STOP.
 /DT/INTER/Keyword3 can be combined with /DT/NODA or /DT/NODA/CST.
 For
Keyword3=AMS
 Advanced Mass Scaling does not modify the global mass, so that the global momentum of the related nodes is conserved. Therefore, /DT/INTER/AMS is more accurate than /DT/INTER/CST, /DT/INTER/CST1 and /DT/INTER/CST2.
 /DT/INTER/AMS is compatible with the following kinematic conditions: boundary conditions, imposed velocities, imposed displacements, imposed accelerations, tied interfaces (/INTER/TYPE2), rigid bodies, fixed rigid walls, rigid links and cylindrical joints.
 /DT/INTER/AMS is compatible with dynamic relaxation (/DAMP) and Rayleigh damping (/DAMP).
 /DT/INTER/AMS will not work if applied to nodes involving rivets (/RIVET) or Lagrange multipliers (e.g. /MPC and /GJOINT). In such cases, an error is output by the Radioss Engine.
 The rigid bodies which are connected to nodes where AMS applies can be activated/deactivated during Radioss Engine run through /RBODY/ON and /RBODY/OFF, but not with sensors.
 /DT/INTER/AMS always applies to the whole model, except
that it is possible to use Elementary time step for AMS (/DT/AMS) on a part group and to use
/DT/INTER/AMS at the same time:
/DT/INTER/AMS will then apply to nodes which are not
belonging to the part group.For example:
 /DT/AMS/1
 $\text{\Delta}{T}_{sca}$ $\text{\Delta}{T}_{\mathrm{min}}$
 Tol_AMS
 /DT/INTER/AMS
 $\text{\Delta}{T}_{sca}$ $\text{\Delta}{T}_{\mathrm{min}}$
 Elementary time step for Advanced Mass Scaling will apply on the part group declared in /AMS of the Radioss Starter Input deck, but /DT/INTER/AMS will apply to nodes which do not belong to the part group.