/SLIPRING/SHELL

Block Format Keyword Define a 2D slipring for seatbelt elements defined with /MAT/LAW119 and /PROP/TYPE9.

Format

(1)	(2)	(3)	(4)	(5)	(7)	(8)	(9)
/SLIPRING/SHELL/`slipring_ID`/`unit_ID`
`slipring_title`
`El_Gr1`	`El_Gr2`	`Gr_Nod`	`Sens_ID`	`Fl_flag`		`Ed_factor`
`fct_ID`₁	`fct_ID`₂	`Fric_d`		`Xscale1`	`Yscale2`		`Xscale2`
`fct_ID`₃	`fct_ID`₄	`Fric_s`		`Xscale3`	`Yscale4`		`Xscale4`

Definition

Field	Contents	SI Unit Example
`slipring_ID`	Slipring identifier. (Integer, maximum 10 digits)
`unit_ID`	(Optional) unit identifier. (Integer, maximum 10 digits)
`slipring_title`	Slipring_title title. (Character, maximum 100 characters)
`El_Gr1`	ID of first group (or set) of elements in slipring. 2 3 (Integer, maximum 10 digits)
`El_Gr2`	ID of second group (or set) of elements in slipring. 2 3 (Integer, maximum 10 digits)
`Gr_Nod`	Group of anchorage nodes. 4 (Integer, maximum 10 digits)
`Sens_ID`	Sensor identifier used for slipring locking. = 0 Slipring is unlocked. (Integer)
`Fl_flag`	Sliding direction control flag. = 0 (Default) Slip in both directions. = 1 Slip from elements of `El_Gr1` to `El_Gr2` only. = 2 Slip from elements of `El_Gr2` to `El_Gr1` only. (Integer)
`Ed_factor`	Exponential decay factor for Coulomb friction. (Real)	$[\frac{s}{m}]$
`fct_ID`₁	Dynamic Coulomb friction coefficient as a function of time identifier. (Integer)
`fct_ID`₂	Dynamic Coulomb friction coefficient as a function of normal force identifier, (Integer)
`Fric_d`	If `fct_ID`₁= 0 Constant dynamic Coulomb friction coefficient. If `fct_ID`₁ > 0 Ordinate scaling factor for function `fct_ID`₁. (Real)
`Xscale1`	Abcissa scaling factor for function `fct_ID`₁. (Real)	$[s]$
`Xscale2`	Abcissa scaling factor for function `fct_ID`₂. (Real)	$[N]$
`Yscale2`	Ordinate scaling factor for function `fct_ID`₂. (Real)
`fct_ID`₃	Static Coulomb friction coefficient as a function of time identifier. (Integer)
`fct_ID`₄	Static Coulomb friction coefficient as a function of normal force identifier. (Integer)
`Fric_s`	If `fct_ID`₃= 0 Constant static Coulomb friction coefficient. If `fct_ID`₃> 0 Ordinate scaling factor for function `fct_ID`₂. (Real)
`Xscale3`	Abcissa scaling factor for function `fct_ID`₃. (Real)	$[s]$
`Yscale4`	Ordinate scaling factor for function `fct_ID`₄. (Real)
`Xscale4`	Abcissa scaling factor for function `fct_ID`₄. (Real)	$[N]$

Comments

The /SLIPRING/SHELL option is an extension to seatbelt shell elements of the /SLIPRING/SPRING. It can be seen as sequence of /SLIPRING/SPRING. The parameters are almost the same; therefore, refer to /SLIPRING/SPRING for a detailed explanation concerning parameters, slipring updates during the run, locking and friction.
The /SLIPRING/SHELL can only be connected to seatbelt shell elements, shells using a seatbelt material (/MAT/LAW119 (SH_SEATBELT)).
The /SLIPRING/SHELL is defined by the 2 groups of shell elements initially connected to the slipring, El_Gr1, El_Gr2 and a group of nodes Gr_Nod used to define the position of the slipring. The common node between the elements of El_Gr1 and El_Gr2 must be at the same coordinates as node_ID₁.

Figure 1.
The slipring must be represented by a line; therefore, the nodes of Gr_Nod must be aligned and can not be nodes of the seatbelt shell elements. All the nodes of Gr_Nod must belong to a single rigid body or boundary condition (all DOF fixed).
At any time, the common nodes of the shell seatbelt elements are kinematically attached to the corresponding anchorage nodes. No other kinematic condition can be applied to theses nodes.
Shell elements that are connected to the slipring are deactivated and are reactivated when they are outside of the slipring. The activation/deactivation of shell elements is progressive, and a scaling factor computed from the distance between the shell element and the slipring is applied on the stresses.