What's New: MD Nastran R3

Local Adaptive Mesh Refinement

  • Local adaptive mesh refinement to automatically alter and control the size of finite element mesh locally

Heat Transfer

  • Added new nonlinear elements such as composite thermal elements 3D. Composite thermal 2D using PCOMP or PCOMPG.
  • The performance for the hemi-cube view factor increases proportionally as the model size increases. A speed up of 33 times has seen been in the test case.
  • New output: added for multiple layers of output for composite thermal element.
  • Transient thermal analysis using SPCD and SPC1
  • Chaining analysis is now available from the thermal analysis step into the structure analysis step in a single run.
  • Minimal Input test file change from previous existing test file in SOL 153 or SOL 159 into

Materials

  • Orthotropic material properties for 3-dimensional and plane strain behavior via the MATORT Bulk Data entry
  • Nonlinear gasket material properties for compression behavior via the MATG Bulk Data entry,
  • Elastoplastic material properties for use in large deformation analysis via the MATEP Bulk Data entry,
  • A new modeling procedure for large strain incompressible materials using a multiplicative
  • decomposition of deformation gradient and is activated using the NLMOPTS Bulk Data entry
  • Anisotropic plasticity (Hill and Barlat models),
  • Pressure dependent plasticity (linear and parabolic Mohr-Coulomb),
  • Viscoplasticity,
  • Cyclic plasticity and viscoplasticity (Chaboche model),
  • Nonlinear stress-strain law for isotropic and orthotropic materials using the advanced nonlinear elements,
  • Viscoelasticity with or without temperature dependent behaviors (power law, WLF and Narayanaswamy models),
  • Creep (Maxwell and Kelvin models),
  • Elastomers (Mooney, Ogden, Arruda-Boyce and Gent models)
  • Shape memory alloy materials (Aruchhio for mechanical and Asaro-Sayeedvafa for thermomechanical models).
  • Existing failure criteria in the MATF option have been enhanced to support progressive failure
  • Micromechanical failure analysis using advanced composites technology from Alphastar Corp.

Elements

  • Lower and higher order plane stress, plane strain, axisymmetric elements for two dimensional analysis
  • Tetrahedral, hexahedral and pentahedral elements for three dimensional analysis
  • Plane stress elements for structural analysis include lower order thin and thick shells using full and reduced integration schemes
  • Several truss and beam elements
  • CBUSH, CWELD and CFAST enhanced for usage in nonlinear SOL400 analysis and support geometrically nonlinear analysis
  • Allow the CBUSH to FUSE at various failure criteria

Analysis Methods

  • Adaptive time stepping scheme enhancements for quasi-static and transient dynamic analysis
  • Enhancements for dynamic contact problems include Generalized-Alpha scheme and a dynamic penetration cutback
  • Linear perturbation analyses, such as normal modes, direct and modal complex eigen values.
  • Brake squeal analysis capability including a combination of general contact with unsymmetrical friction force stiffness matrix and complex eigen value extraction implemented as a special case of linear perturbation

Contact

  • Moment carrying glue
  • Improved flexibility in shell contact
  • In-plane shell edge-to-edge glue
  • Beam to beam contact and general shell edge(-to-edge and –to-surface) contact
  • Optimization of contact constraints
  • Glue control to release specified grids from being glued and breaking glue
  • Easy definition of contact between all bodies

Explicit Nonlinear – SOL700

  • Advanced Fluid Structure Interaction (FSI) – Broadband applications
  • Parallel FSI based on Distributed Memory Parallel Technology
  • Advanced Composites based on AlphaStar – GENOA technology
  • SPH Method – Smooth Particle Hydro-Dynamics
  • Sheet Metal Forming with springback capability
  • Integrated, Multi-disciplinary Fan Blade Out (FBO) and Rotor Dynamics simulation
  • Analysis Chaining: options include Implicit to Explicit (Prestress), Explicit to Explicit (Multiple Droptest) and Explicit to Implicit (springback)
  • New element and material models
  • FAA Hybrid II and III Dummies

Implicit Nonlinear – SOL600

  • Support for very large grid and element IDs (10-digit IDs may be used for grid and elements)
  • Support for multiple RFORCE entries in the same subcase so that different portions of the structure can rotate with different angular velocities or different directions
  • Turn off contact checking in selective subcases
  • New elements include triangular plane stress, solid-shell element and pentahedral 15-node solid element
  • Generalized Alpha method that is superior for difficult dynamics problems involving contact
  • Enhanced composite integration methods to reduce computation times
  • Support for fully nonlinear composites with properties of each layer supporting plasticity and temperature dependency

Noise and Vibration

  • Interchangeable COMPID/COMPNAME fields in all bulk data entries meant for FBA use
  • Support for user load specification in the FBA process
  • Support for responses to both unit loads and user specified loads
  • Connection of scalar points and explicit connection of coincident grid points
  • Flexible connections between degrees of freedom
  • Grounding of connection degrees of freedom
  • Ability to release specific degrees of freedom of connection grid points in the FBA process

Numerical Methods and High Performance Computing

  • Improved computational efficiency and performance for both linear and nonlinear contact analysis, especially for solid elements using CASI element based iterative solver
  • CASI solver available for use in non-linear transient structural analysis
  • Matrix-based iterative solver available for nonlinear static and transient structural analysis
  • Factor matrix caching for Lanczos and nonlinear transient analysis for improved performance
  • TAUCS indefinite solver to improve Lanczos performance
  • Shared memory parallel (SMP) scalability improvements for static analysis

MD Nastran – MD Adams Interoperability

  • MD Database to support multiple flexible bodies in the same database, instead of generating multiple MNF files

Optimization

  • DRESP3 enhancements include – provision for a capability to provide analytic gradients for the response, ability to produce multiple response outputs from a single DRESP3 call and option to reorder finite difference sensitivities
  • Topometry optimization that can be applied to all elements that can be resized through Bulk Data entries DVPREL1 and DVMREL1
  • Topography optimization (bead or stamp optimization) for reinforcement bead patterns
  • Support for permanent glued contact in all SOL200 solutions including sizing, shape, topology, topometry and topography optimization
  • Automatic self-randomization of input file to enable stochastic analysis
  • Random elimination of a specified percentage of CWELD elements contained in a bulk data file for design integrity assessment
  • Support for properties on PCOMPG as design variables
  • Ability to use responses from exterior acoustic analysis
  • Utilize fluid modes as design constraints
  • Nonlinear response optimization capability based on Equivalent Static Loads concept implemented in SOL400

Aeroelasticity and Rotor Dynamics

  • Improved interpolation method that interpolates each term in the generalized aerodynamic matrix individually
  • Storage of spline matrix in sparse format in order to save memory

SCA User Services

  • Nonlinear force elements customizable with an external implementation in the form of a User Defined Service