2021

2021

/ALE/GRID/SPRING

Block Format Keyword Grid nodes are connected with nonlinear springs (those springs have no effect on the material, only on the movement of the grid).

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
/ALE/GRID/SPRING
$Δ t_{0}$		$γ$		$η$		$ν$
`V`_min

Definitions

Field	Contents	SI Unit Example
$Δ t_{0}$	Typical time step (Real)	$[s]$
$γ$	Nonlinearity factor Default = 0.0 (Real)
$η$	Damping coefficient Default = 0.5 (Real)
$ν$	Shear factor Default = 1.0 (Real)
`V`_min	Element with a volume less than `V`_min will be declared Default = -10³⁰ (Real)	$[m^{3}]$

Comments

This option is available for 3D analysis only.
Further explanation about this formulation can be found in ALE Formulation in the Radioss Theory Manual.
Effective time step $Δ t_{0}^{*}$ is computed using damping parameter:(1)
$Δ t_{0}^{*} = \frac{Δ t_{0}}{- η + \sqrt{1 + η^{2}}}$