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.