d5.04.01 Introduce new behavior

Summary:

How do you introduce new behavior?

Here we describe the addition of a new behavior to solve a non-linear problem posed on a structure, with STAT_NON_LINE or DYNA_NON_LINE, for all 2D/3D elements (and shells, pipes, multi-fiber beams,…) or add a new metallurgical behavior in CALC_META.

Essential steps:

• Writing reference documentation R (equations of the law of behavior)

• Modification of the DEFI_MATERIAU catalog (material parameters of the law of behavior)

• Addition of the Python catalog of the behavior relationship

• Choice of the integration method among the following possibilities:

• writing a standalone routine lc0nnintegrating the behavior into an integration point

• explicit integration (ALGO_INTE =” RUNGE_KUTTA “) and writing associated routines

• implicit integration into the environment PLASTI, « complete » implementation (ALGO_INTE =” NEWTON “)

• implicit integration into the environment PLASTI, « easy » implementation (ALGO_INTE =” NEWTON_PERT “)

• Produce tests!

Note: it is also possible to program laws of behavior either in an Umat routine (cf. [U2.10.01]), or using MFront (cf. [U2.10.02] and paragraph 6 of this document).

Table of Contents

• 1. General resolution scheme in STAT_NON_LINE
  • 1.1. Affected calculation options
  • 1.2. Notes concerning the calculation of the residue and the tangent matrix
• 2. Reference documentation and choice of integration method
• 3. Method of operation: catalogs
  • 3.1. Modification of the DEFI_MATERIAU catalog
  • 3.2. Modifying the C_ RELATION catalog
  • 3.3. Add the catalog of the law of behavior
• 4. Deformation at the input of the law of behavior
  • 4.1. Mechanism deform_ldc = “MECANIQUE”
  • 4.2. Mechanism deform_ldc = “TOTALE”
  • 4.3. Mechanism deform_ldc = “OLD”
• 5. Procedure: the routines to write
  • 5.1. First possibility: introduce a new explicit behavior — diagram of RUNGE - KUTTA
  • 5.2. Second possibility: « complete » introduction of new behavior in PLASTI (implicit)
  • 5.3. Third possibility: use of explicit integration routines in an implicit integration with PLASTI
  • 5.4. Fourth possibility: write a standalone lc00nn routine
• 6. Special case of laws MFront
  • 6.1. Catalog for DEFI_MATERIAU and RELATION
  • 6.2. Behaviour catalog
  • 6.3. Order of order of stresses and strains in MFront and aster
• 7. Case of metallurgical behavior laws (CALC_META)
  • 7.1. Modifying the order catalog
  • 7.2. Modifying the behavior catalog
• 8. Validation and maintenance