Loads

New Load Management

Introduction

Nastran and OptiStruct allow loading and boundary conditions to be defined on finite elements. These loads and boundary conditions are commonly applied as distributed loads. Because of their distributed nature, loads and boundary conditions must be carefully applied on individual FE elements. The repetitive nature of FE modeling development creates the overhead of applying loading and boundary conditions for each repetition of new mesh data. New load management aims to simplify this process and solve the problem of redefining loads.

Advantages

HyperMesh creates a load entity for each load solver keyword. Classic load entities can be defined on set entities by defining the underlying region of FE elements, but they cannot address all of the issues of distributed loads. Some of the limitations of classic load support are:

Defining distributed values for loads defined on set entities
Overhead creation and management of load entities on each FE location
Dependency of FE locations for load creation
Limitations of supporting complex boundary condition cards with multiple DOF definitions

The new load management technology offers the following advantages:

Consolidation of loads by common attributes such as SID, Magnitude, etc.
Interrogation of loads is more powerful
Advanced load option support:
- Applying pressure on Nodes
- Applying traction on axisymmetric elements
- Applying pressure on 1D elements based on element orientation
Honoring solver recommendations such as Load on Set
Enhancements to the Solver Browser to handle large numbers of loads
A uniform way to set up a model (end-to-end) through the browser

Objectives

Besides providing a simplified common workflow for managing loads, other engineering load objectives include:

Supporting region independent loads
Defining distributed values for loads defined for each FE location in a set
Adding complete support for all solver cards mapped to classic loads

Classic Load Absorption

Loads created from the panel are called classic loads. Although classic load entities are still supported, their use is not encouraged. New load management allows you to create loads from the Solver Browser. Using the "absorbloads" command, classic load entities can be absorbed into engineering entities.

Advanced Segregation

The advanced segregation feature allows you to spawn new engineering loads from existing engineering loads based on value distribution or topology. You can set up a single load with distributed values and run the "absorbentities" command to obtain multiple meaningful and manageable loads of the same magnitude value.

Realization

A realization command is provided for those who choose to work with classic loads. The "realizefieldloads" command creates classic loads from engineering loads, although it is not the exact reversal of the absorption command.

Load Visualization

Load plotting allows for visualization of distributed load values on an FE region. Different plotting types provide different views of the load.

Vector Plots – display value distribution with the direction of the load
Figure 1.
Advanced Contour Plots – display value distribution with interactive filters
Figure 2.
Contour Plots – display value distribution with respect to the entire model
Figure 3.

Vector plot and contour options are available to visualize LOADADD (OptiStruct) and LOAD (Nastran) by right-clicking and selecting Visualize Loads from the context menu.

Load values can be plotted at specific time stamps for curve-based time dependent loads.

Every load and constraint must be organized into one load collector, and therefore are mutually exclusive to a load collector.

Load Configurations

Load entities have an associated load configuration. A load configuration determines how to draw, store, and work with a load.

Accelerations

Configuration 9 - Acceleration loads allow for an acceleration (length/time²) to be defined on the model.

Accelerations are displayed as a vector with the letter A at the tail end in the modeling window.

Constraints

Configuration 3 - Constraints allow for constrained degrees of freedom to be defined on the model.

Constraints are displayed with a triangle that connects to the node, with the dof numbers that apply to the node beside the triangle in the modeling window.

Fluxes

Configuration 6 - Flux loads are defined as an amount that flows through a unit area per unit time (amount/length²/time). Fluxes are typically used in modeling transport phenomena such as heat transfer, mass transfer, fluid dynamics, and electromagnetism.

Fluxes are displayed as a thick arrow labeled with the word "flux" in the modeling window.

Forces

Configuration 1 - Force loads allow for a concentrated force (mass*length/time²) to be applied to the model.

Forces are displayed as a vector with the letter F at the tail end in the modeling window.

Moments

Configuration 2 - Moment loads allow for a concentrated moment (length*force) to be applied to the model.

Moments are displayed with a double-headed vector with the letter M at the tail end in the modeling window.

Pressures

Configuration 4 - Pressure loads allow for a pressure (force*length²) to be applied to the model.

For most solvers, the pressure load is considered as force/area, therefore the magnitude of the pressure is multiplied by the calculated area of the elements to which it is applied and resolved as concentrated force loads at the associated nodes.

Pressures are displayed as a vector with the letter P at the tail end in the modeling window.

Temperatures

Configuration 5 - Temperature loads allow for a concentrated temperature to be applied to the model.

Temperatures are displayed as a vertical line with the letter T at the top in the modeling window.

Velocities

Configuration 8 - Velocity loads allow for a velocity (length/time) to be applied to the model.

Velocities are displayed as a vector with the letter V at the tail end in the modeling window.

Abaqus Cards

Loads or constraints that are to be used as history data (under *STEP) should be collected into load collectors with the HISTORY card image. These load collectors also need to be added to the corresponding load steps (*STEP). In contrast, loads or constraints for model data should be collected into load collectors with INITIAL_CONDITION card image. They will automatically be written out in the model portion of the Abaqus input deck.

Note: All loads and boundary conditions on sets can be expanded to individual nodes and elements by selecting the Expand load on sets option in the Entity Editor.

Migrated loads:


Configuration	Solver Load	Engineering Type	Description
FORCE	*CLOAD	Directional Force	Concentrated force
MOMENT	*DLOAD	Directional Moment	Concentrated moment
	*DLOAD (CENTRIF)	Directional Moment	Centrifugal force with density
	*DLOAD (CENT)	Directional Moment	Centrifugal force without density
	*DLOAD (CORIO)	Directional Moment	Coriolis force
CONSTRAINTS	*BOUNDARY	Non-Weighted Constraint/Weighted Constraint	Boundary condition
	*BOUNDARY, TYPE=DISPLACEMENT	Weighted Constraint	Enforced displacement
	*BOUNDARY, TYPE=VELOCITY	Weighted Constraint	Enforced velocity
	*BOUNDARY, TYPE=ACCELERATION	Weighted Constraint	Enforced acceleration
	*BOUNDARY, FIXED	Weighted Constraint	Fixed boundary condition for bolts
	*BOUNDARY, USER	Weighted Constraint	User-defined boundary condition
PRESSURE	*DLOAD (TRVEC, TRVECn)	Directional Pressure	General surface traction
	*DLOAD (TRSHR, TRSHRn)	Shear Traction	Shear surface traction
	*DLOAD (PE)	Pipe Pressure	External pipe pressure
	*DLOAD (PI)	Pipe Pressure	Internal pipe pressure
	*DLOAD (PENU)	Pipe Pressure	Non-uniform external pipe pressure
	*DLOAD (PINU)	Pipe Pressure	Non-uniform internal pipe pressure
	*DLOAD (HP, HPn)	Hydrostatic Pressure	Hydrostatic pressure load
	*DLOAD (HPE)	Pipe Pressure	Hydrostatic external pipe pressure
	*DLOAD (HPI)	Pipe Pressure	Hydrostatic internal pipe pressure
	*DLOAD (P, Pn)	Normal Pressure	Pressure load
	*DLOAD (P1, P2)	Beam Pressure	Beam pressure load
	*DLOAD (VBF)	Manufacturing	Viscous body force
	*DSLOAD (P, PNU)	Normal Pressure	Surface pressure uniform/non-uniform
	*DSLOAD (VP)	Manufacturing	Viscous pressure load
	*DSLOAD (HP)	Hydrostatic Pressure	Hydrostatic pressure load on surface
	*DSLOAD (TRVEC)	Directional Pressure	General surface traction
	*DSLOAD (TRSHR)	Shear Traction	Shear surface traction
TEMPERATURE	*BOUNDARY	Thermal	Temperature on nodes
	*BOUNDARY, FIXED	Thermal	Fixed temperature on nodes
	*BOUNDARY, USER	Thermal	User-defined temperature on nodes
FLUX	*BOUNDARY	Electrical Flux	Electrical potential
	*BOUNDARY, FIXED	Electrical Flux	Fixed electrical potential
	*BOUNDARY, USER	Electrical Flux	User-defined electrical potential
ACCELARATION	*DLOAD (ROTA)	Directional Acceleration	Rotational acceleration
	*DLOAD (GRAV)	Directional Acceleration	Gravity load

Classic loads:


Card	Supported Load Types	Description
*BASE MOTION	Constraint	Defines scale factor and DOF for dynamic loads.
*BOUNDARY (electric potential, dof 9)	Flux	Specifies flux boundary conditions for piezoelectric analysis.
*BOUNDARY (structural)	Constraint	Creates structural boundary conditions.
*BOUNDARY (temperature, dof 11)	Temperatures	Specifies temperature boundary conditions.
*CECHARGE	Flux	Specifies concentrated electric charges for piezoelectric analysis.
*CECURRENT	Flux	Specifies concentrated current in electric conduction.
*CFLUX	Flux	Specify concentrated fluxes in heat transfer or mass diffusion analyses.
*CLOAD	Force	Creates concentrated forces.
*CLOAD	Moment	Creates concentrated moments.
*COUPLING	Constraint	Define a surface-based coupling constraint
*DECHARGE	Pressure	Distributes electric charges for piezoelectric analysis.
*DFLUX	Pressure	Specify distributed fluxes in heat transfer or mass diffusion analyses.
*DISTRIBUTING	Constraint	Define a distributing coupling constraint
*DISTRIBUTING COUPLING	Elements	Specify nodes and weighting for distributing coupling elements
*DLOAD	Pressure	Specifies distributed loads
*FILM	Pressure	Define film coefficients and associated sink temperatures.
*KINEMATIC	Multi-point Constraints	Define a kinematic coupling constraint
*KINEMATIC COUPLING	Multi-point Constraints	Constrain all or specific degrees of freedom of a set of nodes to the rigid body motion of a reference node
*MPC	Multi-point Constraints	Define multi-point constraints
*RADIATE	Pressure	Specify radiation conditions in heat transfer analyses
*TEMPERATURE	Temperature	Specifies predefined temperature field.

ANSYS Cards


Card	Supported Load Types	Description
BF	Flux	Defines a nodal body force load.
BF_FLUE	Flux
BF_HGEN	Flux
BF_TEMP	Temperatures
BFE_FLUE	Flux	Defines an element body force load.
BFE_HGEN	Flux
BFE_TEMP	Flux
CE_STRUCT	Equation
CE_THERM	Equation
CE_MAG	Equation
CE_ELEC	Equation
ConvBulkTe	Pressure
ConvFilmCo	Pressure
D_A	Constraint	Vector magnetic potential.
D_CONSTRNT	Constraint	Defines DOF constraints at nodes.
D_MAG	Constraint	Scalar magnetic potential.
D_PRES	Constraint
D_TEMP	Temperature
D_VOLT	Constraint
F_FLOW	Flux	Specifies force loads at nodes.
F_HEAT	Flux
FLOTRAN	Pressure	Specifies "FLOTRAN data settings" as the subsequent status topic. Note: FLOTRAN surface load label “FSI [fluid-structure interaction flag]” is available under pressure load. You must use DOF1 to add value for this label.
FORCE	Force	Selects the element nodal force type for output.
FORCE2	Moment
FSI	Pressure
HFLUX	Pressure
IC_A	Constraint
IC_CONSTRN	Constraint	Specifies initial conditions at nodes.
IC_MAG	Constraint
IC_PRES	Constraint
IC_TEMP	Temperature
IC_VOLT	Constraint
PRESSURE	Pressure
RDSF_EMI	Pressure
RDSF_ENCL	Pressure
SFE	Pressure Convection Heatflux	Defines elemental surface load. Note: Structural, thermal and Fluid labels are covered.
SFE	Structural Thermal Fluid	Surface load Structural label: PRES Thermal label: CONV, HLFUX Fluid label: FSI

LS-DYNA Cards


Card	Supported Load Types	Description
*BOUNDARY_CONVECTION_SET	Flux	Apply a convection boundary condition on a SEGMENT_SET for a thermal analysis.
*BOUNDARY_CYCLIC	Constraint	Define nodes in boundary planes for cyclic symmetry. Optional ID applies to each cyclic definition.
*BOUNDARY_PRESCRIBED_MOTION(Accl)	Acceleration	Define an imposed nodal motion (Acceleration, VAD=1) on a node or a set of nodes.
*BOUNDARY_PRESCRIBED_MOTION(Disp)	Constraint	Define an imposed nodal motion (Displacement, VAD=2) on a node or a set of nodes.
*BOUNDARY_PRESCRIBED_MOTION(Vel)	Velocity	Define an imposed nodal motion (Velocity, VAD=0) on a node or a set of nodes.
*BOUNDARY_PRESCRIBED_MOTION_RIGID(Accl)	Acceleration	Accelerations (VAD=1) can also be imposed on rigid bodies. If the local option is active, the motion is prescribed with respect to the local coordinate system for the rigid body.
*BOUNDARY_PRESCRIBED_MOTION_RIGID(Disp)	Constraint	Displacements (VAD=2, 4) can also be imposed on rigid bodies. If the local option is active, the motion is prescribed with respect to the local coordinate system for the rigid body.
*BOUNDARY_PRESCRIBED_MOTION_RIGID(Vel)	Velocity	Velocities (VAD=0, 3) can also be imposed on rigid bodies. If the local option is active, the motion is prescribed with respect to the local coordinate system for the rigid body.
*BOUNDARY_RADIATION_SET	Flux	Defines surface segment sets that transfer energy by radiation to the environment.
*BOUNDARY_SPC	Constraint	Define nodal single point constraints. Supported OPTION1=NODE, SET. OPTION2=BIRTH_DEATH and OPTION3=ID.
*BOUNDARY_TEMPERATURE	Temperature	Define temperature boundary conditions for a thermal or coupled thermal/structural analysis. Supported OPTION = NODE, SET.
*INITIAL_TEMPERATURE	Temperature	Define initial nodal point temperatures using nodal set IDs or node numbers. This may also be used for sets in which some nodes have other velocities. Supported OPTION = NODE, SET.
*INITIAL_VELOCITY	Velocity	Define initial nodal point velocities using nodal set ID’s. This may also be used for sets in which some nodes have other velocities.
*INITIAL_VELOCITY_NODE	Velocity	Define initial nodal point velocities for a node.
*INITIAL_VELOCITY_RIGID_BODY	Velocity	Define the initial translational and rotational velocities at the center of gravity (c.g.) for a rigid body or a nodal rigid body. This input overrides all other velocity input for the rigid body and the nodes which define the rigid body.
*INITIAL_VELOCITY_GENERATION	Velocity	Define initial velocities for rotating and translating bodies.
*LOAD_BEAM	Pressure	Apply the distributed traction load along any local axis of a beam or a set of beams.
*LOAD_BODY (ACCELERATION)	Acceleration	Define body force loads due to a prescribed base acceleration using global axes directions. Supported OPTION = X, Y, Z.
*LOAD_BODY (VELOCITY)	Velocity	Define body force loads due to a prescribed base angular velocity using global axes directions. Supported OPTION = RX, RY, RZ.
*LOAD_GRAVITY_PART	Acceleration	Define gravity for individual parts. Supported OPTION = PART, SET.
*LOAD_MASK	Pressure	Apply a distributed pressure load over a three-dimensional shell part.
*LOAD_NODE (FORCES)	Force	Apply a concentrated nodal force to a node or each node in a set of nodes. Supported OPTION = POINT, SET and DOF = 1, 2, 3, 4 (Follower).
*LOAD_NODE (MOMENTS)	Force	Apply moments to node or each node in a set of nodes. Supported OPTION = POINT, SET and DOF = 5, 6, 7, 8 (Follower).
*LOAD_RIGID_BODY (FORCES)	Force	Apply a concentrated nodal force to a rigid body. The force is applied at the center of mass. As an option, local axes can be defined for force directions. Supported DOF = 1, 2, 3, 4 (Follower).
*LOAD_RIGID_BODY (MOMENTS)	Force	Apply a concentrated nodal force to a rigid body. The moment is applied around a global axis. As an option, local axes can be defined for moment directions. Supported DOF = 5, 6, 7, 8 (Follower).
*LOAD_SEGMENT	Pressure	Apply the distributed pressure load over one triangular or quadrilateral segment defined by four, six, or eight nodes. Apply the distributed pressure load over each segment in a segment set. Supported OPTION = ID and SET.
*LOAD_SHELL	Pressure	Apply the distributed pressure load over a single shell element or a shell element set. Supported OPTION1 = ELEMENT, SET and OPTION2 = ID.
*LOAD_THERMAL_CONSTANT	Temperature	Define the constant temperature that is applied to a given nodal set.
*LOAD_THERMAL_CONSTANT_NODE	Temperature	Define nodal temperature that remains constant for the duration of the calculation.
*LOAD_THERMAL_LOAD_CURVE	Temperature	Nodal temperatures will be uniform throughout the model and will vary according to a load curve.
*LOAD_THERMAL_VARIABLE	Temperature	Define nodal temperature using node set(s) and temperature as a function of time curve(s).
*LOAD_THERMAL_VARIABLE_NODE	Temperature	Define nodal temperature that is variable during the calculation.

Nastran Cards

Note: Other loads such as SPCADD, MPCADD, FREQ, FREQ1, EIGR, EIGRL, EIGC, EIGP, EIGB, GRAV, and RFORCE are supported as load collectors.


Card	Supported Load Types	Description
ASET	Constraints	Defines degrees-of-freedom in the analysis set (a-set)
ASET1	Constraints	Defines degrees-of-freedom in the analysis set (a-set)
BNDFIX1	Constraints	Defines analysis set (a-set) degrees-of-freedom to be fixed (b-set) during generalized dynamic reduction or component mode synthesis calculations.
BOLTFOR	Flux
BSET1	Constraints	Defines analysis set (a-set) degrees-of-freedom to be fixed (b-set) during generalized dynamic reduction or component mode synthesis calculations.
CSET1	Constraints	Defines analysis set (a-set) degrees-of-freedom to be free (c-set) during generalized dynamic reduction or component modes calculations.
DAREA	Constraints	Defines scale (area) factors for static and dynamic loads. In dynamic analysis, DAREA is used in conjunction with RLOADi and TLOADi entries.
DEFORM	Flux	Defines enforced axial deformation for one-dimensional elements for use in statics problems.
FORCE	Force	Requests the form and type of element force output or particle velocity output in coupled fluid-structural analysis.
MOMENT	Moment	Defines a static concentrated moment at a grid point by specifying a scale factor and a vector that determines the direction.
OMIT1	Constraints	Defines degrees-of-freedom to be excluded (o-set) from the analysis set (a-set).
PLOAD	Pressure	Defines a uniform static pressure load on a triangular or quadrilateral surface comprised of surface elements and/or the faces of solid elements.
PLOAD1	Pressure	Defines concentrated, uniformly distributed, or linearly distributed applied loads to the CBAR or CBEAM elements at user-chosen points along the axis.
PLOAD2	Pressure	Defines a uniform static pressure load applied to CQUAD4, CSHEAR, or CTRIA3 two-dimensional elements. The THRU field is supported for feinput only. On export, additional pressure cards for the range specified are written.
PLOAD4	Pressure	Defines a pressure load on a face of a CHEXA, CPENTA, CTETRA, CTRIA3, CTRIA6, CTRIAR, CQUAD4, CQUAD8, or CQUADR element. The THRU field is supported for feinput only. On export, additional pressure cards for the range specified are written. Unequal nodal pressures are now supported. The average pressure value is used as the magnitude of the pressure for visualization only. The individual field values, P1-P4, can be viewed or edited using the card editor. Updating the magnitude of pressure from the Pressures panel will have no effect on PLOAD4 cards defined using unequal nodal pressures.
QBDY1	Flux	Defines a uniform heat flux into CHBDYj elements.
QSET1	Constraints	Defines generalized degrees-of-freedom (q-set) to be used for generalized dynamic reduction or component mode synthesis.
QVOL	Flux	Volume Heat Addition - Defines a rate of volumetric heat addition in a conduction element.
SPC	Constraints	Defines a set of single-point constraints and enforced motion (enforced displacements in static analysis and enforced displacements, velocities or acceleration in dynamic analysis). Constraints on nodes are supported through SPC cards. PS field in GRID card is not supported. Upon import, any PS entry on the GRID card will be converted into an SPC card.
SPC1	Constraints	Defines a set of single-point constraints. Supported for feinput only. On export, equivalent SPC cards are written. Alternate format with THRU in the fifth field is supported.
SPCD	Constraints	Defines an enforced displacement value for static analysis and an enforced motion value (displacement, velocity or acceleration) in dynamic analysis.
SUPORT	Constraints	Defines determinate reaction degrees-of-freedom in a free body.
SUPORT1	Constraints	Defines determinate reaction degrees-of-freedom (r-set) in a free body-analysis. SUPORT1 must be requested by the SUPORT1 Case Control command.
TIC(D)	Constraints	Transient Initial Condition - Defines values for the initial conditions of variables used in structural transient analysis.
TIC(V)	Constraints	Transient Initial Condition - Defines values for the initial conditions of variables used in structural transient analysis.
TEMP	Temperatures	Defines temperature at grid points for determination of thermal loading, temperature-dependent material properties, or stress recovery.
TEMPBC	Temperatures	Defines the temperature boundary conditions for heat transfer analysis.
USET	Constraints	Defines a degree-of-freedom set.
USET1	Constraints	Defines a degrees-of-freedom set.

OptiStruct Cards

General boundary conditions, such as loads and constraints, should not be collected into specific load collectors. Organizing loads and constraints into a specific load collector may result in an error termination.


Card	Supported Load Types	Description
ASET	Constraints	Defines the boundary degrees-of-freedom of a superelement assembly for matrix reduction.
ASET1	Constraints	Defines the boundary degrees-of-freedom of a superelement assembly for matrix reduction.
BASELIN		Corrects the acceleration record to avoid displacement shift. Note: Bulk Data Entry
CDENST4		Defines a current density on the face of solid elements (HEXA, PENTA, TETRA, PYRA) or on the side of shell elements (TRIA3, TRIA6, QUAD4, QUAD8) in Electrical 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
CURRENT		Defines a static point current at a grid or a set of grids, by specifying a vector, in Electrical analysis. Note: Bulk Data Entry
DAREA	Constraints	Defines scale (area) factors for dynamic loads. DAREA is used in conjunction with RLOAD1, RLOAD2, TLOAD1, and TLOAD2 entries.
DELAY	Constraints	Defines the time delay term τ in the equations of the dynamic loading function. DELAY is used in conjunction with RLOAD1, RLOAD2, TLOAD1, and TLOAD2 entries.
DEFORM	Flux	Defines enforced axial deformation for one-dimensional elements for use in statics problems.
DPHASE	Constraints	Defines the phase lead term $θ$ in the equation of the dynamic loading function. DPHASE is used in conjunction with RLOAD1 and RLOAD2 entries.
FORCE	Force	Defines a static force at a grid point or a `SET` of grid points by specifying a vector.
FORCE1	Force	Used to define a static force by specification of a value and two grid points that determine the direction. It can also be used to define the EXCITEID field (Amplitude "A") of dynamic loads in RLOAD1, RLOAD2, TLOAD1 and TLOAD2 Bulk Data Entries. Additionally, the FORCE1 entry can be defined as Follower Loads in Large Displacement Nonlinear Analysis.
INLTVEL		Defines the Inlet velocity for Darcy Flow Analysis.
MBFRC	Force	Defines a constant force at a grid point by specifying a vector.
MBFRCC	Force	Defines a curve force at a grid point by specifying a vector.
MBMNT	Moment	Defines a constant moment at a grid point by specifying a vector.
MBMNTC	Moment	Defines a curve moment at a grid point by specifying a vector.
MOMENT	Moment	Defines a static moment at a grid point or a `SET` of grid points by specifying a vector.
MOMENT1	Moment	Defines a static moment by specification of a value and two grid points, which determine the direction. It can also be used to define the `EXCITEID` field (Amplitude `A`) of dynamic loads in RLOAD1, RLOAD2, TLOAD1 and TLOAD2 Bulk Data Entries.
MOTNG	Constraint	Defines a constant grid point motion.
MOTNGC	Constraint	Defines a grid point motion vs. time by specifying a curve.
NLENRG		Defines parameters for energy variables printout for implicit nonlinear static and implicit nonlinear transient analyses. Note: Bulk Data Entry
NLPRINT		Controls the printing of certain information to the _nl.out file for nonlinear analysis. Note: Bulk Data Entry
PLOAD	Pressure	Defines a static pressure load on a triangular or quadrilateral element. It can also be used to define the `EXCITEID` field (Amplitude "`A`") of dynamic loads in RLOAD1, RLOAD2, TLOAD1 and TLOAD2 Bulk Data Entries.
PLOAD1	Pressure	Defines concentrated, uniformly distributed, or linearly distributed applied loads to the CBAR or CBEAM elements or a `SET` of such elements at user-chosen points along the axis. It can also be used to define the `EXCITEID` field (Amplitude "`A`") of dynamic loads in RLOAD1, RLOAD2, TLOAD1 and TLOAD2 Bulk Data Entries.
PLOAD2	Pressure	Defines a uniform static pressure load applied to two-dimensional elements, or a `SET` of such elements.
PLOAD4	Pressure	Defines a load on a face of a HEXA, PENTA, TETRA, PYRA, TRIA3, TRIA6, QUAD4, or QUAD8 element. It can also be used to define the `EXCITEID` field (Amplitude "`A`") of dynamic loads in RLOAD1, RLOAD2, TLOAD1 and TLOAD2 Bulk Data Entries. Additionally, the PLOAD4 entry can be defined as Follower Loads in Large Displacement Nonlinear Analysis.
QBDY1	Flux	Defines a uniform heat flux for CHBDYE elements.
QVOL	Flux	Defines a rate of volumetric heat addition in a conduction element.
SPC	Constraint	Defines sets of single-point constraints, enforced displacements for static analysis, and thermal boundary conditions for heat transfer analysis.
SPCD	Constraint	Defines an enforced displacement value for static analysis, an enforced displacement, velocity or acceleration for dynamic analysis and a thermal boundary condition for heat transfer (or transient heat transfer) analysis. It can also be used to define the `EXCITEID` field (Amplitude "A") of dynamic loads in RLOAD1, RLOAD2, TLOAD1 and TLOAD2 Bulk Data Entries.
SPCP		Defines the flow pressure boundary conditions for Darcy Flow Analysis.
SUPORT	Constraint	Defines determinate reaction degrees-of-freedom in a free body.
SUPORT1	Constraint	Defines determinate reaction degrees-of-freedom in a free body.
TEMP	Temperature	Defines temperature at grid points or a SET of grid points for determination of Thermal Loading and Stress recovery.
TIC(D) or (V)	Constraint	Defines values for the initial conditions of variables used in structural transient analysis and explicit analysis. Both displacement and velocity values may be specified at independent degrees-of-freedom.
USET	Constraint	Defines a set of degrees-of-freedom.
USET1	Constraint	Defines a set of degrees-of-freedom.

PAM-CRASH Cards


Card	Supported Load Types	Description
ACC3D /	Acceleration	Imposed accelerations
BOUNC /	Constraints	Define boundary condition
CONLO /	Force(1)	Concentrated nodal load
DIS3D /	Constraints	Imposed displacement
DIS3DM /	Constraints	Imposed minimum displacement
DIS3DX /	Constraints	Imposed maximum displacement
INVEL /	Velocity	Define initial velocity
PREFA /	Pressure(1)	Pressure on shells
RAC3D /	Acceleration	Imposed rotational acceleration
RAN3D /	Constraints	Imposed angular rotations
RDA3D /	Acceleration	Radial 3D boundary conditions
RDD3D /	Constraints
RDV3D /	Velocity	Radial 3D boundary conditions
RVE3D /	Velocity	Imposed rotational velocities
RWALL /		Rigid wall definition
SECFO_PLANE /
VEL3D /	Velocity	Imposed velocities

Permas Cards


Card	Supported Load Types	Description
$ADDMODES	Constraints	Definition of static mode shapes to be added to the set of eigenmodes used for transformation to modal space. If static mode shapes will be added directly to nodes or nodesets (SOURCE=INPUT), the $ADDMODES can be created through the Constraints panel. Click sysid to specify the system regarding to which the modes shall be applied. Use the DOFTYPE button to select an option: DISP, TEMP, PRES, POTE and MATH.
$ADDMODES	Pressure	Definition of static mode shapes to be added to the set of eigenmodes used for transformation to modal space. If mode shapes will be applied based on the natural deformation of elements (SOURCE=INPUT) the $ADDMODES keyword needs to be created here.
$CONLOAD	Force	Definition of concentrated loads at nodal point degrees of freedom.
$CONLOAD	Moment	Definition of concentrated loads at nodal point degrees of freedom.
$DISLOAD PRESS	Pressure	Definition of pressure loads for elements, where loads are given for elements or element sets. Applicable to shells and solids, but also axisymmetric solid elements. Therefore apply a pressure on an HM shell element. Face identifiers are written in this case. On import IDS ELNODES or NODES will be resolved into ELGEO (face identifiers).
$DISLOAD TEMP	Pressure	Nodal temperatures defined on elements or element sets.
$DISLOAD TEMPFILM	Pressure	Surrounding temperatures for convective heat transfer applied on elements or element sets.
$DISLOADN TEMP	Temperature	Nodal temperatures definition applied on nodes or node sets
$DISLOADN TEMPFILM	Temperature	Surrounding temperatures for convective heat transfer applied on nodes or node sets.
$INIVAL	Constraints	Definition of initial values for nodal point degrees of freedom. For $INIVAL source parameter INPUT is currently supported to specify the initial values based on nodal points.
$INERTIA	Pressure	Definition of inertia forces acting on entire component or element sets. Available are force distributions due to linear acceleration, constant or accelerated rotation and coriolis acceleration. Only ACCELERATION and GRAVITY are supported. This card is created in the Pressure panel. Assign to a set of elements, and the set statement displays in the card image. To create the card without a set, create a pressure on a 'dummy' element; the card will be created without a set and can be applied to the whole model.
$INERTIAX	Pressure	Definition of inertia forces acting on entire axisymmetric component or element sets. Available are force distributions due to linear acceleration and constant rotation. Only ACCELERATION and GRAVITY are supported. This card is created in the Pressure panel. Assign to a set of elements, and the set statement displays in the card image. To create the card without a set, create a pressure on a 'dummy' element; the card will be created without a set and can be applied to the whole model.
$MPC GENERAL	Equation	Multipoint constraint definition. The equation needs to be placed into a load collector with card image SUPRESS. By attaching the load collector to a load step with ‘CONSTRAINTS’ attribute set, the $MPCVAL card gets written in the desired $CONSTRAINTS variant.
$PRESCRIBE/ PREVAL	Constraints	Prescribed degrees of freedom/Nodal point values (implemented as HyperMesh constraints)
$SUPPRESS	Constraints	Suppressed degrees of freedom

Radioss Cards


Card	Supported Load Types	Description
/ALE/BCS	Constraint	Describes the ALE boundary conditions.
/BCS	Constraint	Defines boundary conditions on node groups for translational and rotational motion.
/BCS/LAGMUL	Constraint	Defines boundary conditions on node groups using Lagrange multipliers. This keyword is not available for SPMD computation.
/CLOAD	Force	Defines a concentrated force applied to each node of a prescribed nodal group.
/CLOAD	Moment	Defines a concentrated moment applied to each node of a prescribed nodal group.
/CONVEC	Thermal	Describes the free or forced convective flux.
/DFS/DETCORD	Pressure	Set burning times of explosive material elements along a neutral fiber of detonating cord. Neutral fiber is provided with an ordered group of nodes and numerically built by spline interpolation.
/DFS/DETLINE	Pressure	Enable explosive material ignition from a detonation line [A,B]. Point A & B - XYZ coordinate.
/DFS/DETLINE/NODE	Pressure	Enable explosive material ignition from a detonation line [A,B]. Node ID defining Point A & B Coordinates.
/DFS/DETPLAN	Pressure	Describes a planar detonation wave. Node identifier for base point P.
/DFS/DETPLAN/NODE	Pressure	Describes a planar detonation wave. XYZ coordinate for basis point P.
/DFS/DETPOINT	Pressure	Locates the detonation point and set lighting time for an explosive material law, XYZ coordinates.
/DFS/DETPOINT/NODE	Pressure	Locates the detonation point and set lighting time for an explosive material law, node identifier defining ignition coordinates.
/DFS/LASER	Pressure	Enable to model laser impact taking into account laser-matter interaction.
/DFS/WAV_SHA	Pressure	Enables you to shape detonation wave to take into account obstacles.
/EBCS/GRADP0	Pressure	Describes the elementary boundary condition sets. Keyword: Zero pressure gradient.
/EBCS/INIP	Pressure	Describes the elementary boundary condition sets. Keyword: Initial pressure.
/EBCS/INIV	Velocity	Describes the elementary boundary condition sets. Keyword: Initial velocity.
/EBCS/NORMV	Velocity	Describes the elementary boundary condition sets. Keyword: Imposed normal velocity.
/EBCS/PRES	Pressure	Describes the elementary boundary condition sets. Keyword: Imposed density and pressure.
/EBCS/VALVIN	Pressure	Describes the elementary boundary condition sets. Keyword: Inlet valve (Imposed density and pressure).
/EBCS/VALVOUT	Pressure	Describes the elementary boundary condition sets. Keyword: Outlet valve (Imposed density and pressure).
/EBCS/VEL	Velocity	Describes the elementary boundary condition sets. Keyword: Imposed velocity.
/GRAV	Acceleration	Defines gravity load on node group.
/IMPACC	Acceleration	Defines imposed accelerations on a group of nodes.
/IMPDISP	Constraint	Defines imposed displacements on a group of nodes.
/IMPDISP/FGEO	Constraint	Describes the final position of a set of N nodes, input by coordinates.
/IMPFLUX	Thermal	Defines an imposed thermal surface flux on the specified surfaces or a thermal volumetric flux on the specified bricks.
/IMPTEMP	Thermal	Defines imposed temperatures on a group of nodes.
/IMPVEL	Velocity	Defines imposed velocities on a group of nodes.
/IMPVEL/FGEO	Velocity	Describes the final position of a set of N nodes. The final position is provided by a node number. The node may eventually move.
/INITEMP	Thermal	Describes the initial nodal temperature.
/INIVEL/AXIS	Velocity	Initialize both translational and rotational velocities on a group of nodes in a given coordinate system.
/INIVEL/TRA	Velocity	Defines initial velocity on a group of nodes. Initial velocity type: TRA - Translational material velocity.
/INIVEL/ROT	Velocity	Defines initial velocity on a group of nodes. Initial velocity type: ROT - Rotational material velocity.
/INIVEL/T+G	Velocity	Defines initial velocity on a group of nodes. Initial velocity type: T+G - Translational and grid material velocity (only used for ALE material).
/INIVEL/GRID	Velocity	Defines initial velocity on a group of nodes. Initial velocity type: GRID - Grid material velocity (only used for ALE material).
/LOAD/CENTRI	Moment	Apply a centrifugal force on a set of nodes according a body rotational velocity around the defined direction.
/LOAD/PFLUID	Pressure	Simulates hydrodynamic fluid pressure on a structure. The fluid pressure is calculated according to the specified fluid velocity, orientation of the structural surface against the fluid vector and the height of the fluid column above the surface of the structure.
/PLOAD	Pressure	Defines pressure load on a surface.
/RADIATION	Thermal	Describes the imposed radiation flux to environment.
/SPHBCS/SLIDE	Constraint	Describes the SPH symmetry conditions. Type: Material is perfectly sliding along the plane.
/SPHBCS/TIED	Constraint	Describes the SPH symmetry conditions. Type: Material cannot slide along the symmetry plane.