# Groups

Group entities define and store interfaces and rigid walls typically used in contact analysis.

Interfaces
Configurations 1 - 4: Define contact interactions between various parts of the model.
Rigid Walls
Configuration 5: Define a contact or sliding rigid wall in an analysis code.
In all solver interfaces except for LS-DYNA, rigid walls are created as group entities with configuration 5. In the LS-DYNA solver interface, a rigid wall is created as a rigid wall entity.
ALE Setup
Configuration 6: Define input data pertaining to the Arbitrary-Lagrangian-Eulerian LS-DYNA capability.

## Abaqus Cards

Card Description
*BLOCKAGE Control contacting surfaces for blockage.
Note: Must be used in conjunction with the *SURFACE INTERACTION card.
*CHANGE FRICTION Change friction properties.
Note: The Standard template only.

*CLEARANCE Specify a particular initial clearance value and a contact direction for the secondary nodes on a surface.
Note: Must be added to a load step (*STEP) in explicit template.
*COHESIVE BEHAVIOR Used to define surface-based cohesive behavior in a mechanical contact analysis.
Note: It must be used in conjunction with the *SURFACE INTERACTION option.
*CONTACT(General Contact) Begin the definition of general contact.
*CONTACT CLEARANCE Define contact clearance properties.
*CONTACT CLEARANCE ASSIGNMENT Assign contact clearances between surfaces in the general contact domain.
*CONTACT CONTROLS Specify additional controls for contact.
*CONTACT CONTROLS ASSIGNMENT Assign contact controls for the general contact algorithm.
Note: This card is a sub-option in the *CONTACT card image.
*CONTACT DAMPING Define viscous damping between contacting surfaces.
Note: This card is a sub-option in the *SURFACE INTERACTION card image.
*CONTACT EXCLUSIONS Specify self-contact surfaces or surface pairings to exclude from the general contact domain.
Note: This card is a sub-option in the *CONTACT card image.
*CONTACT FORMULATION Specify a nondefault contact formulation for the general contact algorithm.
Note: This card is a sub-option in the * CONTACT card image.
*CONTACT INCLUSIONS Specify self-contact surfaces or surface pairings to include in the general contact domain.
Note: This card is a sub-option in the *CONTACT card image.
*CONTACT INTERFERENCE Prescribe time-dependent allowable interferences of contact pairs and contact elements.
Note: The Standard template only.

*CONTACT PAIR Define surfaces that contact each other.
*CONTACT PROPERTY ASSIGNMENT Assign contact properties for the general contact algorithm.
Note: This card is a sub-option in the *CONTACT card image.
*CONTROLS Reset solution controls.
Note: The Standard template only.
*CONTROLS Reset solution controls.
Note: The Standard template only.
*COUPLING Define a surface-based coupling constraint where the *SURFACE card points to elements.
Note: The *COUPLING is also supported as rigid elements (COUP_KIN) and RBE3 (COUP_DIS) when *SURFACE points to nodes.
*DEBOND Used to specify that crack propagation may occur between two surfaces that are initially partially bonded.
Note: The Standard template only.

The *FRACTURE CRITERION option must appear immediately following this option.

*DIAGNOSTICS Control diagnostic messages.
Note:
Explicit template only.

*DISTRIBUTING Define a distributing coupling constraint.
Note: This card is a sub-option in the *COUPLING card image.

It is also supported as COUP_DIS type rbe3 elements.

*FASTENER (SPOT WELD) Define mesh-independent fasteners.
Note:
*FILTER Define a filter for output filtering.
Note: Explicit template only
*FIXED MASS SCALING Specify mass scaling at the beginning of the step.
Note: Explicit template only.

*FRACTURE CRITERION Used to specify the criterion for crack propagation along initially partially bonded surfaces.
Note: It must appear immediately following the *DEBOND option in Abaqus/Standard and after the *COHESIVE BEHAVIOR option in Abaqus/Explicit.
*FRICTION Specify a friction model.
Note: This card is a sub-option in the *SURFACE INTERACTION card image.
*FRICTION Specify a friction model.
Note:
This card is a sub-option in the *CHANGE FRICTION card image.
*INITIAL CONDITIONS Prescribe initial conditions for an analysis.
*INTEGRATED OUTPUT SECTION Define an integrated output section over a surface with a local coordinate system and a reference point.
*KINEMATIC Define a kinematic coupling constraint.
Note: This card is a sub-option in the *COUPLING card image.

It is also supported as COUP_KIN type rigid elements.

*MODEL CHANGE Remove or reactivate elements and contact pairs.
Note: The Standard template only.

*PRE-TENSION SECTION Associate a pre-tension node with a pre-tension section.
*SHELL TO SOLID COUPLING Define a surface-based coupling between a shell edge and a solid face.
Note:
*SURFACE BEHAVIOR Define alternative pressure-overclosure relationships for contact.
Note: This card is a sub-option in the *SURFACE INTERACTION card image.
*SURFACE INTERACTION Define surface interaction properties.
Note: Explicit template only.

This card is defined from the Property panel in case of Standard 3D and Standard 2D templates.

*SURFACE PROPERTY ASSIGNMENT Assign surface properties to a surface for the general contact algorithm.
Note: This card is a sub-option in the *CONTACT card image.
*TIE Define surface-based tie and cyclic symmetry constraints or coupled acoustic-structural interactions.
*VARIABLE MASS SCALING Specify mass scaling during the step.
Note: Explicit template only.

Card Description
TiedJoint

## LS-DYNA Cards

AnLS-DYNA entity that utilizes a *SET_ [NODE, SHELL, PART, and so on] keyword card belongs to a group, with the exception of Rigid Bodies/RBE2’s.

The difference among configurations is the type of entities contained within a group.
Config 1
Contains main and secondary elements.
Config 2
Contains main elements and secondary nodes.
Config 3
Contains secondary elements.
Config 4
Contains secondary nodes.
Sliding interfaces specifications.
• The Keyword _TITLE option is supported. The _THERMAL(IREAD==3) option is not supported.
• Use the additional cards option in Keyword decks to select number of lines of data. If this is on, two additional cards are available.
• In Structured, additional cards are controlled by using the IREAD variable. Valid values are 0, 1, and 2.
• Boxes, part sets, and sets are supported.
• The $HMNAME fields are used for names. When using the _TITLE option, the 70-character field is considered a comment. • If the line following the keyword (No TITLE option), or the first line of the Structured card contains$HM_NAME, the name supplied is read and used as the group's name. If the string $HM_ID also exists, this is used as the group’s ID. NAME is 16 characters, starting in Column 9. ID field is 8 characters, starting in Column 35. • The solver interface type defines the general type of the LS-DYNA Sliding Interface. Use the to make changes to the LS-DYNA type. Card Description *BOUNDARY_AMBIENT_EOS Defines the IDs of 2 load curves: 1) internal energy per unit reference specific volume and 2) relative volume. *BOUNDARY_FLUX_SET Define flux boundary conditions for a thermal or coupled thermal/structural analysis. *BOUNDARY_SPH_FLOW Define a flow of particle *CONSTRAINED_BUTT_WELD Define a line of coincident nodes that represent a structural butt weld between two parts defined by shell elements. *CONSTRAINED_LAGRANGE_IN_SOLID Provides the coupling mechanism for modeling Fluid-Structure Interaction. *CONSTRAINED_SPOTWELD Defines massless spot welds between non-contiguous nodal pairs. *CONSTRAINED_TIE-BREAK Define a tied shell edge to shell edge interface that can release locally as a function of plastic strain of the shells surrounding the interface nodes. *CONSTRAINED_TIED_NODES_FAILURE Define a tied node set with failure based on plastic strain. *CONTACT_AIRBAG_SINGLE_SURFACE(ID) Define a contact interface. *CONTACT_AIRBAG_SINGLE_SURFACE_MPP(ID) *CONTACT_AUTO_MOVE Move the main surface in a contact definition to close an initial gap between the secondary and main surfaces. *CONTACT_AUTOMATIC_GENERAL(ID) Define a contact interface. *CONTACT_AUTOMATIC_GENERAL_INTERIOR(ID) Define a contact interface. *CONTACT_AUTOMATIC_GENERAL_INTERIOR_MPP(ID) *CONTACT_AUTOMATIC_GENERAL_MPP(ID) *CONTACT_AUTOMATIC_NODES_TO_SURFACE(ID) Define a contact interface. *CONTACT_AUTOMATIC_NODES_TO_SURFACE_MPP(ID) *CONTACT_AUTOMATIC_NODES_TO_SURFACE_SMOOTH(ID) Define a contact interface. *CONTACT_AUTOMATIC_NODES_TO_SURFACE_SMOOTH_MPP(ID) *CONTACT_AUTOMATIC_ONE_WAY_SURFACE_TO_SURFACE(ID) *CONTACT_AUTOMATIC_ONE_WAY_SURFACE_TO_SURFACE_ORTHO_FRICTION(ID) *CONTACT_AUTOMATIC_ONE_WAY_SURFACE_TO_SURFACE_SMOOTH(ID) *CONTACT_AUTOMATIC_ONE_WAY_SURFACE_TO_SURFACE_TIEBREAK(ID) *CONTACT_AUTOMATIC_SINGLE_SURFACE(ID) *CONTACT_AUTOMATIC_SINGLE_SURFACE_MORTAR(ID) Define a contact interface. *CONTACT_AUTOMATIC_SINGLE_SURFACE_MPP(ID) *CONTACT_AUTOMATIC_SINGLE_SURFACE_SMOOTH(ID) *CONTACT_AUTOMATIC_SINGLE_SURFACE_SMOOTH_MPP(ID) *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE(ID) *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE_MORTAR(ID) *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE_MORTAR_TIED(ID) *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE_MPP(ID) *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE_ORTHO_FRICTION(ID) *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE_SMOOTH(ID) *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE_SMOOTH_MPP(ID) *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE_THERMAL_FRICTION(ID) *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE_TIEBREAK(ID) *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE_TIEBREAK_MPP(ID) *CONTACT_CONSTRAINT_NODES_TO_SURFACE(ID) *CONTACT_CONSTRAINT_NODES_TO_SURFACE_MPP(ID) *CONTACT_CONSTRAINT_SURFACE_TO_SURFACE(ID) *CONTACT_CONSTRAINT_SURFACE_TO_SURFACE_MPP(ID) *CONTACT_DRAWBEAD(ID) *CONTACT_DRAWBEAD_MPP(ID) *CONTACT_ENTITY(ID) Define a contact entity *CONTACT_ENTITY_MPP(ID) *CONTACT_ERODING_NODES_TO_SURFACE(ID) *CONTACT_ERODING_NODES_TO_SURFACE_MPP(ID) *CONTACT_ERODING_SINGLE_SURFACE(ID) *CONTACT_ERODING_SINGLE_SURFACE_MPP(ID) *CONTACT_ERODING_SURFACE_TO_SURFACE(ID) *CONTACT_ERODING_SURFACE_TO_SURFACE_MPP(ID) *CONTACT_FORCE_TRANSDUCER_CONSTRAINT(ID) *CONTACT_FORCE_TRANSDUCER_CONSTRAINT_MPP(ID) *CONTACT_FORCE_TRANSDUCER_PENALTY(ID) *CONTACT_FORCE_TRANSDUCER_PENALTY_MPP(ID) *CONTACT_FORMING_NODES_TO_SURFACE(ID) *CONTACT_FORMING_NODES_TO_SURFACE_MPP(ID) *CONTACT_FORMING_NODES_TO_SURFACE_SMOOTH(ID) *CONTACT_FORMING_NODES_TO_SURFACE_SMOOTH_MPP(ID) *CONTACT_FORMING_ONEWAY_SURFACE_TO_SURFACE(ID) *CONTACT_FORMING_ONEWAY_SURFACE_TO_SURFACE_CONSTRAINED_OFFSET(ID) *CONTACT_FORMING_ONEWAY_SURFACE_TO_SURFACE_CONSTRAINED_OFFSET_MPP(ID) *CONTACT_FORMING_ONEWAY_SURFACE_TO_SURFACE_CONSTRAINED_OFFSET_SMOOTH(ID) *CONTACT_FORMING_ONEWAY_SURFACE_TO_SURFACE_CONSTRAINED_OFFSET_SMOOTH_MPP(ID) *CONTACT_FORMING_ONEWAY_SURFACE_TO_SURFACE_MPP(ID) *CONTACT_FORMING_ONEWAY_SURFACE_TO_SURFACE_SMOOTH(ID) *CONTACT_FORMING_ONEWAY_SURFACE_TO_SURFACE_SMOOTH_MPP(ID) *CONTACT_FORMING_SURFACE_TO_SURFACE(ID) *CONTACT_FORMING_SURFACE_TO_SURFACE_CONSTRAINED_OFFSET(ID) *CONTACT_FORMING_SURFACE_TO_SURFACE_CONSTRAINED_OFFSET_MPP(ID) *CONTACT_FORMING_SURFACE_TO_SURFACE_CONSTRAINED_OFFSET_SMOOTH(ID) *CONTACT_FORMING_SURFACE_TO_SURFACE_CONSTRAINED_OFFSET_SMOOTH_mpp(ID) *CONTACT_FORMING_SURFACE_TO_SURFACE_MORTAR(ID) *CONTACT_FORMING_SURFACE_TO_SURFACE_MPP(ID) *CONTACT_FORMING_SURFACE_TO_SURFACE_SMOOTH(ID) *CONTACT_FORMING_SURFACE_TO_SURFACE_SMOOTH_MPP(ID) *CONTACT_INTERIOR(ID) Define interior contact for foam hexahedral and tetrahedral elements. *CONTACT_INTERIOR_MPP(ID) *CONTACT_NODES_TO_SURFACE(ID) *CONTACT_NODES_TO_SURFACE_INTERFERENCE(ID) *CONTACT_NODES_TO_SURFACE_INTERFERENCE_MPP(ID) *CONTACT_NODES_TO_SURFACE_MPP(ID) *CONTACT_NODES_TO_SURFACE_SMOOTH(ID) *CONTACT_NODES_TO_SURFACE_SMOOTH_MPP(ID) *CONTACT_ONE_WAY_SURFACE_TO_SURFACE(ID) *CONTACT_ONE_WAY_SURFACE_TO_SURFACE_INTERFERENCE(ID) *CONTACT_ONE_WAY_SURFACE_TO_SURFACE_INTERFERENCE_CONSTRAINED_OFFSET(ID) *CONTACT_ONE_WAY_SURFACE_TO_SURFACE_INTERFERENCE_CONSTRAINED_OFFSET_MPP(ID) *CONTACT_ONE_WAY_SURFACE_TO_SURFACE_INTERFERENCE_MPP(ID) *CONTACT_ONE_WAY_SURFACE_TO_SURFACE_MPP(ID) *CONTACT_ONE_WAY_SURFACE_TO_SURFACE_SMOOTH(ID) *CONTACT_ONE_WAY_SURFACE_TO_SURFACE_SMOOTH_MPP(ID) *CONTACT_RIGID_BODY_ONE_WAY_TO_RIGID_BODY(ID) Define rigid surface contact. *CONTACT_RIGID_BODY_ONE_WAY_TO_RIGID_BODY_MPP(ID) *CONTACT_RIGID_BODY_TWO_WAY_TO_RIGID_BODY(ID) *CONTACT_RIGID_BODY_TWO_WAY_TO_RIGID_BODY_MPP(ID) *CONTACT_RIGID_NODES_TO_RIGID_BODY(ID) *CONTACT_RIGID_NODES_TO_RIGID_BODY_MPP(ID) *CONTACT_RIGID_SURFACE(ID) *CONTACT_RIGID_SURFACE_MPP(ID) *CONTACT_SINGLE_EDGE(ID) *CONTACT_SINGLE_EDGE_MPP(ID) *CONTACT_SINGLE_SURFACE(ID) *CONTACT_SINGLE_SURFACE_MPP(ID) *CONTACT_SLIDING_ONLY(ID) *CONTACT_SLIDING_ONLY_MPP(ID) *CONTACT_SLIDING_ONLY_PENALTY(ID) *CONTACT_SLIDING_ONLY_PENALTY_MPP(ID) *CONTACT_SPOTWELD(ID) *CONTACT_SPOTWELD_MPP(ID) *CONTACT_SPOTWELD_WITH_TORSION(ID) *CONTACT_SPOTWELD_WITH_TORSION_MPP(ID) *CONTACT_SURFACE_TO_SURFACE(ID) *CONTACT_SURFACE_TO_SURFACE_CONTRACTION_JOINT(ID) *CONTACT_SURFACE_TO_SURFACE_INTERFERENCE(ID) *CONTACT_SURFACE_TO_SURFACE_INTERFERENCE_CONSTRAINED_OFFSET *CONTACT_SURFACE_TO_SURFACE_INTERFERENCE_CONSTRAINED_OFFSET_MPP(ID) *CONTACT_SURFACE_TO_SURFACE_INTERFERENCE_MPP(ID) *CONTACT_SURFACE_TO_SURFACE_MPP(ID) *CONTACT_SURFACE_TO_SURFACE_SMOOTH(ID) *CONTACT_SURFACE_TO_SURFACE_SMOOTH_MPP(ID) *CONTACT_SURFACE_TO_SURFACE_THERMAL_FRICTION(ID) *CONTACT_THERMAL_SURFACE_TO_SURFACE_(ID) *CONTACT_THERMAL_SURFACE_TO_SURFACE_MPP(ID) *CONTACT_TIEBREAK_NODES_TO_SURFACE(ID) *CONTACT_TIEBREAK_NODES_TO_SURFACE_MPP(ID) *CONTACT_TIEBREAK_SURFACE_TO_SURFACE(ID) *CONTACT_TIEBREAK_SURFACE_TO_SURFACE_MPP(ID) *CONTACT_TIED_NODES_TO_SURFACE(ID) *CONTACT_TIED_NODES_TO_SURFACE_CONSTRAINED_OFFSET(ID) *CONTACT_TIED_NODES_TO_SURFACE_CONSTRAINED_OFFSET_MPP(ID) *CONTACT_TIED_NODES_TO_SURFACE_MPP(ID) *CONTACT_TIED_NODES_TO_SURFACE_OFFSET(ID) *CONTACT_TIED_NODES_TO_SURFACE_OFFSET_MPP(ID) *CONTACT_TIED_SHELL_EDGE_TO_SURFACE(ID) *CONTACT_TIED_SHELL_EDGE_TO_SURFACE_BEAM_OFFSET(ID) *CONTACT_TIED_SHELL_EDGE_TO_SURFACE_BEAM_OFFSET_MPP(ID) *CONTACT_TIED_SHELL_EDGE_TO_SURFACE_CONSTRAINED_OFFSET(ID) *CONTACT_TIED_SHELL_EDGE_TO_SURFACE_CONSTRAINED_OFFSET_MPP(ID) *CONTACT_TIED_SHELL_EDGE_TO_SURFACE_MPP(ID) *CONTACT_TIED_SHELL_EDGE_TO_SURFACE_OFFSET(ID) *CONTACT_TIED_SHELL_EDGE_TO_SURFACE_OFFSET_MPP(ID) *CONTACT_TIED_SURFACE_TO_SURFACE(ID) *CONTACT_TIED_SURFACE_TO_SURFACE_CONSTRAINED_OFFSET(ID) *CONTACT_TIED_SURFACE_TO_SURFACE_CONSTRAINED_OFFSET_MPP(ID) *CONTACT_TIED_SURFACE_TO_SURFACE_MPP(ID) *CONTACT_TIED_SURFACE_TO_SURFACE_OFFSET(ID) *CONTACT_TIED_SURFACE_TO_SURFACE_OFFSET_MPP(ID) *CONTACT_TIED_SURFACE_TO_SURFACE_TITLE(ID) *CONTACT_2D_AUTOMATIC_SURFACE_TO_SURFACE(ID) Define a two-dimensional contact or slide line. *CONTACT_2D_AUTOMATIC_SURFACE_TO_SURFACE_THERMAL_TITLE(ID) *CONTACT_2D_AUTOMATIC_SURFACE_TO_SURFACE_THERMAL_TITLE_MPP(ID) *CONTACT_2D_AUTOMATIC_SURFACE_TO_SURFACE_TITLE(ID) *CONTACT_2D_AUTOMATIC_SURFACE_TO_SURFACE_TITLE_MPP(ID) *CONTACT_2D_AUTOMATIC_TIED_TITLE Defines a two-dimensional contact or slide line. May be used with rigid body material. *DATABASE_FSI Used to output information about certain coupled Lagrangian surfaces. *DATABASE_NODAL_FORCE_GROUP Define a nodal force group for output into ASCII file NODFOR and the binary file XTFILE. *ELEMENT_TRIM Define a part subset to be trimmed by *DEFINE_CURVE_TRIM *INITIAL_GAS_MIXTURE Used to specify a) which ALE multi-material groups may be present inside an ALE mesh set at time zero and b) the corresponding reference gas temperature and density which define the initial thermodynamic state of the gases. *INITIAL_VOID (PART and SET) Define initial voided part set IDs or part numbers. *INITIAL_VOLUME_FRACTION Define initial volume fractions of different materials in multi-material ALE elements. *INITIAL_VOLUME_FRACTION_GEOMETRY Volume filling command for defining the volume fractions of various ALE multi-material group that can occupy certain regions in some specified ALE mesh set. *SET_MULTI-MATERIAL_GROUP_LIST(TITLE) Defines an ALE multi-material set ID which contains a collection of one or more ALE multi-material group IDs. ## Nastran Cards Contact, thermal analysis definitions and non-structural mass are represented using group entities. Card Description AESURF Specifies an aerodynamic control surface as a member of the set of aerodynamic extra points. BCBODY Defines a flexible or rigid contact body in 2D or 3D. Note: Defined through surface properties in BSURF. On export, turn on solver option "Export as old contact." BCBODY1 Defines a flexible or rigid contact body in 2D and 3D. Note: Use Contact Browser. BCONECT Defines the touching and touched contact bodies. Note: Use Contact Browser. BCTABL1 Defines a contact table. Note: Use Contact Browser. BCTABLE Defines a contact table. Note: Defined through BCONECT/BTABL1. On export, turn on solver option "Export as old contact." BCTSET Note: Defined using the Interfaces panel BSURF Defines a contact body or surface defined by Element IDs. Note: Defined using the Interfaces panel BSURFS 3D Contact Region Definition by Solid Elements. Note: NX Nastran only. Defined using the Interfaces panel CONDUCTION Defines CHBDYE secondary elements used for thermal conduction analysis. Note: Defined using the Interfaces panel CONVECTION Defines CHBDYE secondary elements used for thermal convection analysis, and also allows for CONV continuation cards to be defined. Note: Has PCONV card image. Defined using the Interfaces panel. NSM1 Defines non-structural mass per unit length/area on properties or elements. Note: Defined using the NSM panel. NSML1 Defines lumped non-structural mass on properties or elements. Note: Defined using the NSM panel. PCONV Specifies the free convection boundary condition properties of a boundary condition surface element used for heat transfer analysis. Note: Defined using the Interfaces panel, using CONVECTION group type. RADIATION Defines CHBDYE secondary elements used for thermal radiation analysis. Note: Has RADM card image. Defined using the Interfaces panel. RADM Defines the radiation properties of a boundary element for heat transfer analysis. Note: Defined using the Interfaces panel, using RADIATION group type. SPBLND1 Defines a strip based blending of two splines. SPBLND2 Defines a curve based blending of two splines. SPRELAX Defines relaxation of a spline based on an adjacent spline. SPLINE1 Defines a surface spline for interpolating motion and/or forces for aeroelastic problems on aerodynamic geometries defined by regular arrays of aerodynamic points. SPLINE2 Defines a beam spline for interpolating motion and/or forces for aeroelastic problems on aerodynamic geometries defined by regular arrays of aerodynamic points. SPLINE4 Defines a curved surface spline for interpolating motion or forces for aeroelastic problems on general aerodynamic geometries. SPLINE5 Defines a 1D beam spline for interpolating motion and/or forces for aeroelastic problems on aerodynamic geometries. SPLINE6 Defines a 6DOF or 3DOF finite surface spline for interpolating motion and/or forces between two meshes. SPLINE7 Defines a 6DOF finite beam spline for interpolating motion and/or forces between two meshes. SPLINRB Defines a rigid body spline for interpolating motion or forces for aeroelastic problems on general aerodynamic geometries. ## OptiStruct Cards Contact, thermal analysis definitions, multi-body dynamics bodies, non-structural mass, rigid walls and section outputs are represented using group entities. Card Description CLRNC Defines parameters for clearance and threaded bolts geometry. The CLRNC Bulk Data Entry is selected on the CLEARANCE field in the CONTACT Bulk Data Entry. Note: Bulk Data Entry CONTACT Defines a contact interface for Small Displacement Nonlinear Analysis (NLSTAT), Nonlinear Transient Dynamics (NLGEOM), and Contact-based Thermal Analysis (HEAT). Note: Bulk Data Entry CONDUCTION Defines CHBDYE secondary elements used for thermal conduction analysis. Note: Bulk Data Entry CONVECTION Defines CHBDYE secondary elements used for thermal conduction analysis, and also allows for CONV continuation cards to be defined. Note: Bulk Data Entry GROUND Defines a ground body out of a list of finite element properties, elements, and grid points. Note: Bulk Data Entry MBCNTDS Defines a Multibody Contact between a set of nodes and a deformable surface. Note: Bulk Data Entry MBCNTR Defines a Multibody contact between rigid bodies. Note: Bulk Data Entry NSGE1 Defines non-structural material damping for a list of elements or properties (Alternate format). Note: Bulk Data Entry NSGE Defines non-structural material damping for a list of elements or properties. Note: Bulk Data Entry NSM1 Defines non-structural mass per unit area or per unit length for a list of elements or properties. Note: Bulk Data Entry NSML1 Defines lumped non-structural mass for a list of elements or properties. Note: Bulk Data Entry PCONV Defines a free convection boundary condition properties. Note: Bulk Data Entry PFBODY Defines a flexible body out of a list of finite element properties, elements, and grid points. Note: Bulk Data Entry PRBODY Defines a rigid body out of a list of finite element properties, elements and grid points. Note: Bulk Data Entry SECT Defines a section for force output in geometric nonlinear analysis. Note: Bulk Data Entry TIE Defines a tied contact in Linear Static Analysis (STATICS) and Small Displacement Nonlinear Analysis (NLSTAT). Penalty-based and MPC-based TIE contacts are available and can be selected using CONTPRM, TIE. Note: Bulk Data Entry XDAMP Defines the values for Raleigh damping for geometric nonlinear dynamic analysis. Note: Bulk Data Entry ## PAM-CRASH 2G Cards Card Description CNTAC / NTYPE = 1 Special sliding without separation CNTAC / NTYPE = 10 Internal solid anti-collapse contact CNTAC / NTYPE = 21 Body-to-multiplane contact CNTAC / NTYPE = 33 Symmetric node-to-segment contact with edge treatment CNTAC / NTYPE = 34 Non-symmetric node-to-segment contact with edge treatment CNTAC / NTYPE = 36 Self-impacting node-to-segment contact with edge treatment CNTAC / NTYPE = 37 Enhanced self-impacting contact for airbags CNTAC / NTYPE = 43 Edge-to-edge main-secondary contact CNTAC / NTYPE = 44 Node-to-segment-oriented contact with smooth contact surface CNTAC / NTYPE = 46 Edge-to-edge self-impacting contact CNTAC / NTYPE = 54 Non-symmetric-oriented contact CNTAC / NTYPE = 61 Node-to-analytical surface contact CNTAC / NTYPE = 154 Implicit small sliding contact MASS_GES / Added mass definition (only when IDNOD = 0) NSMAS / Non-structural mass definition NSMAS2/ Alternate mass distribution method TIED / Node-surface tied interface ## Permas Cards Card Description$CONTACT Contact definitions
$MPC ISURFACE Coupling of two surfaces$MPC WLSSURFACE/ WLDSURFACE Weld connection between nodes and surfaces
$PRETENSION PLANE Pretension definition without detailing the threaded connection.$PRETENSION THREAD Modeling a threaded pretension section

Card Description
/INICONT Container definition for ALE material.
Note: Block Format Keyword
/INIVOL Defines material in the ALE containers.
Note: Block Format Keyword
/INTER Describes the interfaces.
Note: Block Format Keyword
/INTER/LAGMUL/TYPE7 Describes the Lagrange Multiplier interface TYPE7. Multi usage impact interface between a main surface and a list of secondary nodes.
Note: Block Format Keyword
/INTER/TYPE1 Defines a fluid-structure interaction. Lagrangian elements (structure) can interact with ALE elements, which model a viscous fluid.
Note: Block Format Keyword
/INTER/TYPE2 Defines a TYPE2 tied interface that connects a set of secondary nodes to a main surface. It can be used to connect coarse and fine meshes, model spotwelds, rivets, and so on.
Note: Block Format Keyword
/INTER/TYPE3 Simulates impacts between two surfaces (with oriented segments). This interface works properly if the two surfaces are simply convex.
Note: Block Format Keyword
/INTER/TYPE5 Simulates impacts between a main surface and a list of secondary nodes.
Note: Block Format Keyword
/INTER/TYPE6 Simulates contact between two rigid bodies with tabulated input of the contact force. It works similar to interface TYPE3. Contact force between the bodies can be input as a function of maximal penetration. The interface also allows you to input a force function for unloading.
Note: Block Format Keyword
/INTER/TYPE7 Multi-usage impact interface, modeling contact between a main surface and a group of secondary nodes. It is also possible to consider heat transfer and heat friction.
Note: Block Format Keyword
/INTER/TYPE8 Simulates drawbeads. It is mainly used in the process industry to model metal forming. Drawbeads are used to prevent the metal strip from sliding during the stamping process. Normals of the main segments must be oriented toward the secondary nodes (unsorted group).
Note: Block Format Keyword
/INTER/TYPE9 Defines the ALE Lagrange with void opening and free space. Non-impacted ALE nodes are on a free surface. The grid velocity is equal to the material velocity in normal direction. The normal of the main surface elements must be oriented toward the secondary nodes.
Note: Block Format Keyword
/INTER/TYPE10 Tied contact with void.
Note: Block Format Keyword
/INTER/TYPE11 Simulates impact between edge to Edge or lines. A line can be a beam or truss element or a shell edge or spring elements.
Note: Block Format Keyword
/INTER/TYPE12 Defines fluid to fluid contact and enables the transmission of flow between two ALE surfaces (main and secondary side). The secondary node velocities are interpolated from main surface values. Then convective fluxes are calculated between the two surfaces.
Note: Block Format Keyword
/INTER/TYPE14 Simulates impacts between a hyper-ellipsoidal rigid main surface and a list of secondary nodes. The hyper-ellipsoidal surface is treated as an analytical surface (hyper-ellipsoidal surfaces are only discretized for post-processing). For this interface, generally, use a mesh whose size is finer than the lowest semi- axis of main surface. The main surface must be a MADYMO hyper-ellipsoidal surface or a Radioss hyper-ellipsoidal surface.
Note: Block Format Keyword
/INTER/TYPE15 Ellipsoidal Surfaces to Elements Contact. It is a penalty contact interface without damping. This interface replaces interface TYPE14, especially if the mesh is coarser than the ellipsoid size. The secondary surface must be a set of 3-node or 4-node segments (i.e. any kind of surface; except ELLIPS and MDELLIPS surfaces). The main surface must be a MADYMO hyper-ellipsoidal surface or a Radioss hyper-ellipsoidal surface, and Interface does not allow penetrations up to half the ellipsoid.
Note: Block Format Keyword
/INTER/TYPE18 Defines the Euler/Lagrange or ALE/Lagrange contact. Euler-Lagrange or ALE-Lagrange contact is the contact between a Lagrangian main surface and a list of Eulerian or ALE secondary nodes. Material velocity for all secondary nodes is imposed by main surface with a penalty formulation. ALE secondary node grid velocity is not modified by this interface.
Note: Block Format Keyword
/INTER/TYPE19 Combination of interface TYPE7 and TYPE11, with common input based on the same secondary/main surfaces. Secondary node group for interface TYPE7, as well as secondary and main line segments used by equivalent TYPE11 interface are virtually generated from these input surfaces.
Note: Block Format Keyword
/INTER/TYPE20 A general single surface or surface to surface contact interface. Edge to edge contact is also possible. Penalty stiffness is constant and therefore the time step is not affected (for standard penalty stiffness). This contact interface can replace interface TYPE3, TYPE5, TYPE7, TYPE11 or TYPE19. The interface is basically defined in terms of one or two surfaces. If only one surface is used, this surface is self-impacting. If two surfaces are defined, nodes of surface two impact surface one. A symmetric treatment can be activated. Edges of surface one and two can be taken into account for the contact. Nodes can be added to surface.
Note: Block Format Keyword
/INTER/TYPE21 Specific interface between a non-deformable main surface and a secondary surface designed for stamping. All nodes of the main surface must belong to the rigid body.
Note: Block Format Keyword
/INTER/TYPE22 Defines Cartesian Cut Cell Method for FSI between a lagrangian surface and a fluid domain. Coupling Interface Type 22 was designed for ditching application and currently requires a smooth lagrangian surface. User surface is used to cut the fluid mesh, this way and contrary to Interface Type 18 based on a penalty method, there is no numerical parameter to define.
Note: Block Format Keyword
/INTER/TYPE23 Defines a contact interface for airbag fabrics, modeling contact between a main surface and a secondary surface which are supposed to belong to an airbag. This is a soft penalty contact which can deal with penetrations and intersections often coming in the folded airbag mesh. This interface can be used for self-impacting.
Note: Block Format Keyword
/INTER/TYPE24 Defines a general contact interface, optional single surface or surface to surface or nodes to surface contacts could be defined. Penalty stiffness is constant and therefore the time step is not affected (for standard penalty stiffness). This contact interface can replace interface type 3, 5, 7, or 20.
Note: Block Format Keyword
/INTER/TYPE25 TYPE25 is a general nodes to surface contact interface using the penalty method. The penalty stiffness is constant and therefore the time step is not affected for standard penalty stiffness. Unlike TYPE7 contact, solid elements have zero contact gap thickness. Three types of contact inputs can be defined: single surface, surface to surface, or nodes to surface. This contact interface can replace interface TYPE3, TYPE5, TYPE7, TYPE20 (obsolete) or TYPE24.
Note: Block Format Keyword

## Samcef Cards

Card Description Examples
.BOLT Defines a bolt contact.

.BOLT I 1 NDIST 1155 MACRO 2090 $GROUP "PRETENS_1" METHOD 1 ! "BOLT_1" .CLM NOEUD I 1155 CHA COMP 1 VAL 150000.0 .BOLT I 2 NDIST 1156 MACRO 3090 FIX 2$
GROUP "PRETENS_2" METHOD 2 ! "BOLT_2"

.CLM NOEUD I 1156 DEP VAL 10.5 COMP 1

.MCT Defines a flexible contact.

.MCT I 10 GROUP 17 GTAR 23 OPT 3 ! Contact default

.MCT I 20 GROUP 65 GTAR 12 OPT 2 NLIM -1 UN3 1 DMIN -0.0245 KSMO 1 ! Advanced contact

.MCT I 30 GROUP 45 GTAR 75 OPT 2 UN3 1 OCPO 2 KSMO 1 ! Glue contact

.STI Defines a glue contact.

.STI I 1 GROUP 17 23 PROJ 0! Glue default

.STI I 2 GROUP 35 64 ! Advanced glue

.ZYG Defines a periodic condition or cyclic condition - explicit mode contact.

.ZYG GROUP "secondary_nodes" "main" $TRAN 0.0 1.0 0.0 ! "contact_Periodic" .ZYG GROUP "secondary_nodes" "main"$
WAVE                1 $AXE X$
ORIGIN       0.88366595       1.02703438            -40.0 $ANGL 45.0$
PROJ 0 ! "contact_cyclic"

.ZYG_AUTO Defines a cyclic condition - automatic mode contact.

.ZYG AUTO GROUP "auto_elements" $WAVE 0$

AXE                 Y \$

ORIGIN      -8.41253531        5.4064082     -16.47058824 ! "contact_Auto_Cyclic"