LS-DYNA 971-7600.129 released

The release provides fixes and extensions.

Many new capabilities were added during 2003-2005 to create version 971 of LS-DYNA. Initially, the intent was to quickly release version 971 after 970 with the implicit capabilities fully functional for distributed memory processing using MPI. Unfortunately, the effort required for parallel implicit was grossly underestimated, and, as a result, the release has been delayed. Because of the delay, version 971 has turned into a major release. Some of the new features, listed below, were also added to later releases of version 970. The new explicit capabilities are implemented in the MPP version and except for one case, in the SMP version as well.

Below is list of new capabilities and features:

Airbag

• A simplified method for using the ALE capability with airbags is now available with the keyword *AIRBAG_ALE.

• Airbag simulations by using ALE method can be switched to control volume method by *ALE_CV_SWITCH.
• *ALE_FSI_SWITCH_MMG is implemented to switch between ALE multi-material groups to treat immersed FSI problems.
• Type 9 option is added in *ALE_REFERENCE_SYSTEM_GROUP to deal complex ALE mesh motions including translation, rotation, expansion and contraction, etc.
• *ALE_MODIFIED_STRAIN allows multiple strain fields in certain ALE elements to solve sticking behavior in FSI. (MPP underdevelopment)
• *ALE_FSI_PROJECTION is added as a new constraint coupling method to solve small pressure variation problem. (MPP underdevelopment)

• Case control using the *CASE keyword, which provides a way of running multiple load cases sequentially within a single run.

Constrained

• Butt weld definition by using the *CONSTRAINED_BUTT_WELD option which makes the definition of butt welds simple relative to the option: *CONSTRAINED_GENERALIZED_WELD_BUTT.
• Boundary constraint in a local coordinate system using *CONSTRAINED_LOCAL keyword.
• A cubic spline interpolation element is now available, *CONSTRAINED_SPLINE.
• New options in *CONSTRAINED_LAGRANGE_IN_SOLID.
• New coupling method for fluid flowing through porous media are implemented as type 11 (shell) and type 12 (solid) in *CONSTRAINED_LAGRANGE_IN_SOLID.

Contact

• New option to forming contact: *CONTACT_FORMING_ONE_WAY_SURFACE_TO_SURFACE_SMOOTH, which use fitted surface in contact calculation.
• Added new contact type *CONTACT_GUIDED_CABLE.

Control

• H-adaptive fusion is now possible as an option with the control input, *CONTROL_ADAPTIVE.
• Added a parameter on, *CONTROL_ADAPTIVE, to specify the number of elements generated around a 90 degree radius. A new option to better calculate the curvature was also implemented.
• Added a new keyword: *CONTROL_ADAPTIVE_CURVE, to refine the element along trimming curves.
• Birth and death times for implicit dynamics on the keyword *CONTROL_IMPLICIT_DYNAMICS.
• Added an option to scale the spot weld failure resultants to account for the location of the weld on the segment surface, see *CONTROL_SPOTWELD_BEAM.
• Added an option automatically replace a single beam spot weld by an assembly of solid elements using the same ID as the beam that was replaced, see *CONTROL_SPOTWELD_BEAM.
• Static implicit analyses in of a structure with rigid body modes is possible using the option, *CONTROL_IMPLICIT_INERTIA_RELIEF.
• Shell element thickness updates can now be limited to part ID’s within a specified set ID, see the *CONTROL_SHELL keyword. The thickness update for shells can now be optionally limited to the plastic part of the strain tensor for better stability in crash analysis.
• Solid element stresses in spot welds are optionally output in the local system using the SWLOCL parameter on the *CONTROL_SOLID keyword.
• SPOTHIN option on the *CONTROL_CONTACT keyword cards locally thins the spot welded parts to prevent premature breakage of the weld by the contact treatments.
• New function: *CONTROL_FORMING_PROJECT, which can initial move the penetrating slave nodes to the master surface
• New function *CONTROL_FORMING_TEMPLATE, which allows user to easily set up input deck. Its function include auto-position, define travel curve, termination time, and most of the forming parameters for most of the typical forming process.
• New function *CONTROL_FORMING_USER, *CONTROL_FORMING_POSITION, and *CONTROL_FORMING_TRAVEL, when used together, can allow user to define a typical forming process.
• Added option in *CONTROL_CPU to output the cpu and elapsed time into the GLSTAT file.
• Added an option, IERODE, on the *CONTROL_OUTPUT keyword to include eroded energies by part ID into the MATSUM file. Lumped mass kinetic energy is also in the MATSUM file as part ID 0.
• Added an option, TET10, on the *CONTROL_OUTPUT keyword to output ten connectivity nodes into D3PLOT database rather than 4.
• EFGPACK is implemented in addition to BCSLIB-EXT solver on the keyword *CONTROL_EFG.

Damping

• Damping defined in *DAMPING_PART_STIFFNESS now works for the Belytschko Schwer beam element.

Database

• Circular cut planes are available for *DATABASE_CROSS_SECTION definitions.
• New binary database FSIFOR for fluid structure coupling.
• Added *DATABASE_BINARY_D3PROP for writing the material and property data to the first D3PLOT file or to a new database D3PROP.
• *DATABASE_EXTENT_BINARY has new flags to output peak pressure, surface energy density, nodal mass increase from mass scaling, thermal fluxes, and temperatures at the outer surfaces of the thermal shell.
• Two NODOUT files are now written: one for high frequency output and a second for low frequency output.
• Added option, _MASS_PROPERTIES, to include the mass and inertial properties in the GLSTAT and SSSTAT files.
• Nodal mass scaling information can now be optionally written to the D3PLOT file.
• *DATABASE_BINARY_FSIFOR outputs fluid-structure interaction data to binary file.
• *DATABASE_FSI_SENSOR outputs ALE element pressure to ASCII file dbsor.

Define

• Tubular drawbead box option for defining the elements that are included in the drawbead contact, see *DEFINE_BOX_DRAWBEAD.
• New function: *DEFINE_CURVE_DRAWBEAD, allow user to conveniently define drawbead by using curves (in x, y format or iges format)
• New function: *DEFINE_DRAWBEAD_BEAM, which allows user to conveniently define drawbead by using beam part ID, and specify the drawbead force.
• Analytic function can be used in place of load curves with the option *DEFINE_CURVE_FUNCTION.
• Friction can now be defined between part pair using the *DEFINE_FRICTION input.
• New keyword: *DEFINE_CURVE_TRIM_3D, to allow trimming happens based on blank element normal, rather than use pre-defined direction
• A new trimming algorithm was added: *DEFINE_CURVE_TRIM_NEW, which allow seed node to be input and is much faster then the original algorithm.
• A new keyword, *DEFINE_HEX_SPOTWELD_ASSEMBLY, is available to define a cluster of solid elements that comprise a single spotweld.
• The definition of a vector, see *DEFINE_VECTOR, can be done by defining coordinates in a local coordinate system.
• The definition of a failure criteria between part pairs is possible with a table defined using the keyword, *DEFINE_SPOTWELD_FAILURE_RESULTANTS.
• A new keyword, *DEFINE_CONNECTION_PROPERTIES is available for defining failure properties of spot welds.
• Added *DEFINE_SET_ADAPTIVE to allow the adaptive level and element size to be specified by part ID or element set ID.
• Static rupture stresses for beam type spot welds can be defined in the keyword input, *DEFINE_SPOTWELD_RUPTURE_STRESS.

Element

• New keyword, *ELEMENT_SOLID_T4TOT10 to convert 4 node tetrahedron elements to 10 node tetrahedron elements.
• New keyword, *ELEMENT_MASS_PART defines the total additional non-structural mass to be distributed by an area weighted distribution to all nodes of a given part ID.
• Section properties can be define in the *ELEMENT_BEAM definitions for resultant beam elements using the SECTION option.
• Physical offsets of the shell reference surface can be specified on the shell element cards, see the OFFSET option on *ELEMENT_SHELL.
• Shell formulations 4, 11, 16, and 17 can now model rubber materials.
• Added a new seatbelt pretensioner type 7 in which the pretensioner and retractor forces are calculated independently and added.
• A new composite tetrahedron element made up from 12 tetrahedron is now available as solid element type 17.
• The Hughes-Liu beam has been extended to include warpage for open cross-sections.
• A resultant beam formulation with warpage is available as beam type 12.
• Two nonlinear shell elements are available with 8 degrees-of-freedom per node to include thickness stretch.
• Tetrahedron type 13, which uses nodal pressures, is now implemented for implicit applications.
• Cohesive solid elements are now available for treating failure.
• Seatbelt shell elements are available for use with the all seatbelt capabilities.
• Superelements can now share degrees-of-freedom and are implemented for implicit applications under MPI.
• A user defined element interface is available for solid and shell elements. Thermal shells are available for treating heat flow through shell elements.
• EFG shell formulations 41 and 42 are implemented for explicit analysis.
• EFG MPP version is available for explicit analysis.
• EFG fast transformation method is implemented in the EFG solid formulation.
• EFG Semi-Lagrangian kernel and Eulerian kernel options are added for the foam materials.
• EFG 3D adaptivity is implemented for the metal materials.
• EFG E.O.S. and *MAT_ELASTIC_FLUID materials are included in the 4-noded background element formulation.
• Shell thickness option for coupling type 4.
• Bulk modulus based coupling stiffness.
• Shell erosion treatment.
• Constitutive models added for truss elements:
  • *MAT_MUSCLE
• For beam elements:
  • *MAT_MOMENT-CURVATURE
• For shell elements:
  • *MAT_RESULTANT_ANISOTROPIC
  • *MAT_RATE_SENSITIVE_COMPOSITE_FABRIC
  • *MAT_SAMP-1
  • *MAT_SHAPE_MEMORY is now implemented for shells.
• For shell and solid elements:
  • *MAT_BARLAT_YLD2000 for anisotropic aluminum alloys.
  • *MAT_SIMPLIFIED_RUBBER_WITH_DAMAGE
  • *MAT_VISCOELASTIC_THERMAL
  • *MAT_THERMO_ELASTO_VISCOPLASTIC_CREEP
• For the solid elements:
  • *MAT_ARUP_ADHESIVE
  • *MAT_BRAIN_LINEAR_VISCOELASTIC
  • *MAT_CSCM for modeling concrete.
  • *MAT_PLASTICITY_COMPRESSION_TENSION_EOS for modeling ice.
  • *MAT_COHESIVE_ELASTIC
  • *MAT_COHESIVE_TH
  • *MAT_COHESIVE_GENERAL
  • *MAT_EOS_GASKET
  • *MAT_SIMPLIFIED_JOHNSON_COOK is now implemented for solids.
  • *MAT_PLASTICITY_WITH_DAMAGE is now implemented for solids.
  • *MAT_SPOTWELD_DAIMLERCHRYSLER

• User defined equations-of-state are now available.

Hourglass

• Added hourglass control type 7 for solid elements for use when modeling hyperelastic materials.

Include

• File names can be located in remote directories and accessed through the *INCLUDE_PART keyword.
• New features to *INCLUDE_STAMPED_PART : two different mirror options, user-defined searching radius.

Initial

• New keyword option, SET, for *INTIAL_STRESS_SHELL_SET allows a set of shells to be initialized with the state of stress.
• *INTIAL_STRESS_SECTION allows for stress initialization across a cross-section, which consists of solid elements.
• An option, IVATN, is available for setting the velocities of slaved nodes and parts for keyword, *INITIAL_VELOCITY_GENERATION.
• *INITIAL_VOLUME_FRACTION_GEOMETRY uses an enhanced algorithm to handle both concave and convex geometries and substantially reduce run time.

Integration

• Twenty-two built-in cross-section are now available in the definition of beam integration rules, see *INTEGRATION_BEAM.
• The possibility of changing material types is now available for shells using the user defined integration rule, see *INTEGRATION_SHELL.

Interface

• The interface springback file created by using the keyword, *INTERFACE_SPRINGBACK is now optionally written as a binary file.
• There is now an interface with the MOLDFLOW code.
• Enable/disable interface force file.

Keyword

• New option allows the number of cpu’s to be specified on the *KEYWORD input.
• An optional input line for *KEYWORD allows the definition of a prefix for all file names created during a simulation. This allow multiple jobs to be executed in the same directory.

• Body force loads can now be applied in a local coordinate system for *LOAD_BODY.
• A pressure loading feature allows moving pressures to be applied to a surface to simulate spraying a surface with stream of fluid through a nozzle. See keyword *LOAD_MOVING_PRESSURE.
• Convection heat transfer activates by *LOAD_ALE_CONVECTION in ALE FSI analysis.

Material

• Thermal expansion can be added to any material by the keyword, *MAT_ADD_THERMAL_EXPANSION.
• Curves can now be used instead of eight digitized data points in the material model *MAT_ELASTIC_WITH_VISCOSITY_CURVE.
• New options for spot weld failure in *MAT_SPOTWELD, which apply to beam and solid elements.
• Failure criteria based on plastic strain to failure is added to material *MAT_ANISOTROPIC_VISCOPLASTIC.
• Strain rate failure criterion is added to material *MAT_MODIFIED_PIECEWISE_LINEAR_PLASTICITY.
• Strain rate scaling of the yield stress can now be done differently in tension and compression in material with separate pressure cut-offs in tension and compression in material model *MAT_PLASTICITY_TENSION_COMPRESSION.
• The RCDC model is now available to predict failure in material *MAT_PLASTICITY_WITH_DAMAGE.
• Two additional yield surfaces have been added to material *MAT_MODIFIED_HONEYCOMB to provide more accurate predictions of the behavior of honeycomb barrier models.
• Unique coordinate systems can be assigned to the two nodal points of material *MAT_1DOF_GENERALIZED_SPRING.
• Poisson’s ratio effects are available in foam defined by load curves in the material *MAT_SIMPLIFIED_RUBBER/FOAM.
• Failure effects are available in the rubber/foam material defined by load curves in the *MAT_SIMPLIFIED_RUBBER/FOAM_WITH_FAILURE.
• The material option *MAT_ADD_EROSION now allows the maximum pressure at failure and the minimum principal strain at failure to be specified.
• Strains rather than displacements can now be used with the material model for discrete beams, *MAT_GENERAL_NONLINEAR_6DOF_DISCRETE_BEAM.
• New option for MAT_TRANSVERSELY_ANISOTROPIC_ELASTIC_PLASTIC_(ECHANGE), which allow two ways to change the Young’s modulus during forming simulation.
• New Material model: *MAT_HILL_3R : includes the shear term in the yield surface calculation by using Hill’s 1948 an-isotropic material model.
• New Material model: *MAT_KINEMATIC_HARDENING_TRANSVERSELY_ANISOTROPIC : which integrates Mat #37 with Yoshida’s two-surface kinematic hardening model.
• Improved formulation for the fabric material, *MAT_FABRIC for formulations 2, 3, and 4. The improved formulations are types 12, 13, and 14.
• *MAT_ALE_VISCOUS now supports Non-Newtonian viscosity by power law or load curve.
• *MAT_GAS_MIXTURE supports nonlinear heat capacities.
• Constitutive models added for truss elements:
  • *MAT_MUSCLE
• For beam elements:
  • *MAT_MOMENT-CURVATURE
• For shell elements:
  • *MAT_RESULTANT_ANISOTROPIC
  • *MAT_RATE_SENSITIVE_COMPOSITE_FABRIC
  • *MAT_SAMP-1
  • *MAT_SHAPE_MEMORY is now implemented for shells.
• For shell and solid elements:
  • *MAT_BARLAT_YLD2000 for anisotropic aluminum alloys.
  • *MAT_SIMPLIFIED_RUBBER_WITH_DAMAGE
  • *MAT_VISCOELASTIC_THERMAL
  • *MAT_THERMO_ELASTO_VISCOPLASTIC_CREEP
• For the solid elements:
  • *MAT_ARUP_ADHESIVE
  • *MAT_BRAIN_LINEAR_VISCOELASTIC
  • *MAT_CSCM for modeling concrete.
  • *MAT_PLASTICITY_COMPRESSION_TENSION_EOS for modeling ice.
  • *MAT_COHESIVE_ELASTIC
  • *MAT_COHESIVE_TH
  • *MAT_COHESIVE_GENERAL
  • *MAT_EOS_GASKET
  • *MAT_SIMPLIFIED_JOHNSON_COOK is now implemented for solids.
  • *MAT_PLASTICITY_WITH_DAMAGE is now implemented for solids.
  • *MAT_SPOTWELD_DAIMLERCHRYSLER

• The option *NODE_TRANSFORMATION allows a node set to be transformed based on a transformation defined in *DEFINE_TRANSFORMATION.

Parameter

• Parameters can be defined in FORTRAN like expressions using *PARAMETER_EXPRESSION.

• Eight-character alphanumeric labels can now be used for the parameters SECID, MID, EOSID, HGID, and TMID on the *PART keyword.
• A part can be moved in a local coordinate system in *PART_MOVE.
• A simplified method for defining composite layups is available with *PART_COMPOSITE.

• A part set can now be defined by combining other part sets in *SET_PART_ADD.

Termination

• Termination of the calculation is now possible if a specified number of shell elements are deleted in a give part ID. See *TERMINATION_DELETED_SHELLS.

Restart_Input_Data

• The rigid body inertia can be changed in restart via *CHANGE_RIGID_BODY_INERTIA.

• A new keyword *DELETE_FSI allows the deletion of coupling definitions.