/DT/SPHCEL/Keyword3

Engine Keyword Generates the SPH cells time step control type.

Format

/DT/SPHCEL/Keyword3

$Δ T_{s c a}$ $Δ T_{\min}$

Field	Contents	SI Unit Example
`Keyword3`	Time step control type: `DEL` The SPH cell which is controlling the time step is removed so that the constant time step, $Δ T_{\min}$ can be maintained. `STOP` The run will stop, if the SPH cells time step reaches $Δ T_{\min}$ and a restart file will be written. `KILL` The computation is killed, if the SPH cells time step reaches $Δ T_{\min}$ If `Keyword3` is not specified, that is, /DT/SPHCEL, then the shell elements will use the $Δ T_{\min}$ is not used.
$Δ T_{s c a}$	Scale factor on time step for option `SPHCEL`.
$Δ T_{\min}$	Minimum time step for option `SPHCEL`.

Field

Contents

SI Unit Example

Keyword3

Time step control type:

DEL: The SPH cell which is controlling the time step is removed so that the constant time step, $Δ T_{\min}$ can be maintained.
STOP: The run will stop, if the SPH cells time step reaches $Δ T_{\min}$ and a restart file will be written.
KILL: The computation is killed, if the SPH cells time step reaches $Δ T_{\min}$

If Keyword3 is not specified, that is, /DT/SPHCEL, then the shell elements will use the $Δ T_{\min}$ is not used.

Δ T_{s c a}

Scale factor on time step for option SPHCEL.

Δ T_{\min}

Minimum time step for option SPHCEL.

This option can be used with the /DT/NODA. In such case, the criteria for deleting a SPH cell (or stopping, or killing the computation) is:
(1)
$Δ T_{sca} \cdot \sqrt{\frac{2 m}{K^{*}}} \leq Δ t_{\min}$

with $K^{*}$ being the stiffness based on SPH interaction.
Nodal time step is generally more robust.