SWGEN
SWGEN, Ecomp
,
SWRD
, NCM1
,
NCM2
, SND1
,
SND2
, SHRD
,
DIRX
, DIRY
,
DIRZ
, ITTY
,
ICTY
Creates a new spot weld set.
Ecomp
Name to identify the new spot weld, used for the element component containing the new contact, target, and beam elements generated for the spot weld set.
START
—
Initiate the spot weld generation process.
END
—
Finish the spot weld generation process.
When using
Ecomp
to define the component name of the spot weld element, do not begin the name withSTAR
orEND
. Those values are reserved for starting and finishing a block of multiple SWGEN commands.SWRD
Spot weld radius.
NCM1
Name of a component containing nodes on the first spot weld surface, a meshed area number for the surface, or the name of a component group containing nodal components of multiple surfaces to be weld.
NCM2
Name of a component containing nodes on the second spot weld surface, or a meshed area number for the surface.
SND1
Node number of the first spot weld node corresponding to the first surface (
NCM1
). This node can be on or close to the first surface. For this use ofSND1
, you must also input a node number forSND2
.To define multiple spot welds between two surfaces, use the
SND1
field in one of these ways:To input the name of a table array parameter containing the node information for each spot weld. The node information should be presented as node numbers, geometric coordinates, or both. The table name must be enclosed in "%" signs (for example, %
tabname
%).To input the name of a nodal component group of predefined nodes. This use is only supported for node-to-surface configuration of spot welds.
To input the name of an element component group of predefined joints or beam elements. This use is only supported for node-to-surface configuration of spot welds.
When generating multiple spot welds,
SND2
is ignored.SND2
Node number of the second spot weld node corresponding to the second surface (
NCM2
). This node can be on or close to the second surface. Mechanical APDL creates the node if not specified.SHRD
Search radius. Defaults to 4 times the spot weld radius
SWRD
.DIRX
,DIRY
,DIRZ
Spot weld projection direction in terms of normal X, Y, and Z components.
ITTY
Target element type ID.
ICTY
Contact element type ID.
NTOS
—
Generate the node-to-surface configuration of the spot welds with force-distributed constraints.
NTS2
—
Generate the node-to-surface configuration of the spot welds with rigid surface constraints.
Notes
This command creates a new spot weld set. You can add more surfaces to the set using SWADD after the initial SWGEN command. However, the maximum number of allowable surfaces (including the two surfaces used for the original set) for each spot weld set is 11.
Ecomp
, SWRD
,
NCM1
, NCM2
, and
SND1
must be specified. SND2
,
SHRD
, DIRX
,
DIRY
, DIRZ
,
ITTY
, ICTY
are optional inputs. If
the second spot weld node (SND2
) is specified, that node is used
to determine the spot weld projection direction, and DIRX
,
DIRY
and DIRZ
are ignored.
To reduce the spot weld generation time of large assembly models
where multiple SWGEN commands are issued, define the multiple
SWGEN commands within a block initiated with
SWGEN,START
and finished with
SWGEN,END
. The block must be ended with
SWGEN,END
if it is started with
SWGEN,START
. Do not use any commands other
than SWGEN and CMGRP within the block. Select all
elements and nodes, and create all components prior to the
SWGEN,START
command.
If NCM1
is defined as a component group
name to add multiple surfaces to the node-to-surface configuration of the spot weld, no
SWADD command is needed. NCM2
is ignored. The
component group of multiple surfaces must be defined using the CMGRP
command prior to the SWGEN. The maximum allowed number of surfaces for
each spot weld set is 8. Using SWGEN to generate multiple spot welds is
only supported for node-to-surface configuration of spot welds
If ITTY
(target element ID) is
specified, the following corresponding target element key option must be set: KEYOPT(2) =
1.
If ICTY
(contact element ID) is
specified (only valid for pilot node configuration), the following corresponding contact
element key options must be set: KEYOPT(2) = 2, KEYOPT(4) = 1, KEYOPT(12) = 5.
If ICTY
(contact element ID) is
specified as NTOS
or NTS2
,
node-to-surface configuration of spot-welds is defined. In this
configuration, each spot weld consists of a beam element and two node-to-surface MPC
contact pairs. Each contact pair has contact element (CONTA175)
which is defined by the associated spot-weld node. The target elements
(TARGE170) are formed by a group of surface nodes lying within the
region of the search radius on the spot weld surfaces. The program creates real constant
IDs for each layer, and proper contact and target element type IDs. The following
corresponding contact element key options are set: KEYOPT(2) = 2,
KEYOPT(12) = 5. For ICTY
=NTOS
,
target elements KEYOPT(5) = 4 is set for defining the force-distributed
constraint type. For ICTY
=NTS2
, target
elements KEYOPT(5) = 7 is set for defining the rigid surface constraint
type.
After SND1
and SND2
are projected
onto surface 1 and surface 2, respectively, two new pilot-nodes (which represent the spot
weld nodes) are generated at the locations of SND1
and
SND2
and meshed with TARGE170 target
elements (TSHAP,PILO).
By default, the contact pair created at each spot weld surface is an MPC-based force-distributed constraint. To use force-distributed constraints based on the Lagrange multiplier method, you must set KEYOPT(2) = 3 for the contact elements after SWGEN is issued. To use rigid constraints instead of force-distributed constraints, you must set KEYOPT(4) = 0 for the contact elements after SWGEN is issued.
To automatically define multiple spot welds between two surfaces,
use tabular input in the SND1
field. The table array that you
input must be a 2D array parameter. For more information, see Generation of Multiple Spot Welds in the Contact Technology Guide.
To use the relaxation method to eliminate overconstraint, you must set KEYOPT(11) = 1 for the target elements after SWGEN is issued.
Issue SWLIST and SWDEL to list or delete spot welds, respectively. SWLIST and SWDEL are not supported for node-to-surface configuration. For more information about defining spot welds, see Creating a Basic Spot Weld Set with SWGEN.