LS-DYNA Basic Training
Input Deck StructureBasic Cards
V1.0
Frequently Used Building Blocks of DYNA-deck *NODE *ELEMENT *PART *SECTION *MATERIAL *LOAD *BOUNDARY *DEFINE
*CONTROL *DATABASE *PART_INERTIA *PART_CONTACT
KEYWORD RELATIONSHIP
*ELEMENT_SHELLEID PID N1 N2 N3 N4
*NODENID X Y Z TC RC
*PARTPID SID MID …
*SECTION_SHELLSID EFORM SHRF NIP PROPT QR …
*MAT_ELASTICMID RO E PR DA DB K
*NODE
FORMAT: (I8,3E16.0,2E8.0)NID X Y Z TC RCNID:- Node idX,Y,Z – Co-ordinatesTC – Translational constrains (0-7)RC – Rotational Constrains (0-7)
Here elemental connectivity and part ids are given.
*ELEMENT_SOLID-To define 3D solid element
*ELEMENT_SHELL-To define 3-4 noded elements (3d-shell,membrane,etc)
*ELEMENT_BEAM-To define 2 noded elements (3d-beams,truss,etc.)
*ELEMENT_DISCRETE-To define spring or dampers
*ELEMENT_MASS-To define a lumped mass on node
*ELEMENT_SEATBELT-To define a seat belt element
*ELEMENT
*SECTION
Here element formulation, integration rule, nodal thicknesses, c/s properties are defined.
*SECTION_SHELL Use default formulation for most of the cases Thickness, formulation
*SECTION_SOLID Formulation
*SECTION_BEAM Use formulation 1 or 2 Beam section values
*MaterialHere material properties are defined MAT_ELASTIC (MAT1)
Density, Modulus, Poisson’s ratio For parts not expected to yield
MAT_PIECEWISE_LINEAR_PLASTICITY (MAT24)
Density, Modulus, Poisson’s ratio Stress-strain curve or yield stress and tangent modulus For parts which may yield/fail
MAT_RIGID (MAT20) Density, Modulus, Poisson’s ratio Model rigid parts
*DEFINE*DEFINE_BOX
-Used to define box like volume. (Box volume is then referenced in *initial_velocity, *contact, *load cards)
*DEFINE_COORDINATE_** -Used to define local co-ordinate systems. (Referenced in *load, *boundary cards)
*DEFINE_CURVE -Used to define curves. (Referenced in *mat, *load cards)
*DEFINE_VECTOR -Used to define vectors
*DEFINE_SD_ORIENTATION -Used to define orientation vectors for spring and dampers.
*LOAD*LOAD_NODE_POINT
-Used to define nodal forces on individual node
*LOAD_NODE_SET -Used to define nodal forces on set of nodes
*LOAD_SEGMENT -Used to define pressure on segment
*LOAD_SEGMENT_SET -Used to define pressure on set of segments
*LOAD_SHELL_** -Used to define pressure on one or more shell elements
*LOAD_BODY -Used to define body loads ( accn and angular velocities)
*LOAD_RIGID_BODY -Used to apply nodal forces to rigid body
*BOUNDARY
*BOUNDARY_PRESCRIBED_MOTION_OPT1_OPT -Used to apply imposed nodal motion (disp, velocity or accn)
OPT1 can be:- NODE, SET, RIGID, RIGID_LOCALOPT2 can be:- ID
*BOUNDARY_SPC_OPT1_OPT2 -Used to define local co-ordinate systems. (Referenced in *load, *boundary cards)OPT1 can be:- NODE, SETOPT2 can be:- ID
*CONTROL
*CONTROL_ENERGY – Control for energy dissipation (default)
*CONTROL_HOURGLASS – Hourglass control
*CONTROL_OUTPUT – To set output parameters
*CONTROL_PARALLEL – Controls parallel processing
*CONTROL_SHELL – Controls for computing shell response
*CONTROL_TERMINATION – Controls termination time
*CONTROL_TIMESTEP – Setting up time step
*CONTROL_ACCURACY – Control parameters for improving accuracy of the solution
*CONTROL_CONTACT – Controls contact behavior
*DATABASE
*DATABASE_OPTION -To specify the output frequency of ASCII output files
*DATABASE_BINARY_OPTION -To specify the output frequency of binary output
files
Other Important *Part Cards
*PART_INERTIA- Allows inertia properties and initial conditions to be defined rather than calculated from FE.
Important parameters:Translational massInitial translations / Initial rotations
*PART_CONTACT- Allows part based contact option to be used with automatic contacts.
Important option :OPTT – optional contact thicknessSFT – optional contact thickness scale factor. It scales the
true thickness.SSF – Slave contact stiffness scale factor.