NLENRG

Bulk Data Entry Defines parameters for energy variables printout for implicit nonlinear static, implicit nonlinear transient analyses, and explicit dynamic analysis.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
NLENRG ID PARAMi VALUEi
The following continuation line is optional and can be used to activate printout of energy variables for selected element SETs.
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
“ESET” SET1 SET2 etc.
The following continuation line is optional and can be used to activate printout of energy variables for selected contact interfaces.
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
“CONTACT” CID1 CID2 etc.
The following continuation line is optional and can be used to activate printout of energy variables for selected (per-property) groups of CGAP/CGAPG elements.
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
“PGAP” PGID1 PGID2 etc.

Example

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
NLENRG 99 FREQ 2
  ESET 1001 1002
CONTACT ALL
PGAP 100 200

Definitions

Field Contents SI Unit Example
ID Each NLENRG Bulk Data Entry must have a unique ID.

No default (Integer > 0)

 
PARAMi Name of parameter.  
VALUEi Value of parameter.  
ESET Keyword indicating energy variables are to be printed for selected element SETs.  
SETi Element SET identification number.

No default (Integer > 0)

  
CONTACT Keyword indicating energy variables are to be printed for selected contact interfaces.  
CIDi
ALL
All the contact interfaces.
Integer > 0
Contact interface identification number.

No default

  
PGAP Keyword indicating energy variables are to be printed for selected CGAP/CGAPG elements.  
PGIDi
ALL
All the PGAP properties.
Integer > 0
PGAP property identification number.

No default

 
PARAMi VALUEi SI Unit Example
FREQ Output frequency in increments. This is applicable to both Implicit and Explicit nonlinear subcases.

Default = 1 (for Implicit analysis)

Default = 100 (for Explicit analysis)

(Integer > 0)

  
HG Control for output of HyperGraph data files (*.nlm) for Implicit nonlinear subcases. 3 4
0
HyperGraph data output is not activated.
1 (Default)
HyperGraph data output is activated for global energy variables.
2
HyperGraph data output is activated for the global energy variables and per-entity energy variables.
 

Comments

  1. The NLENRG Bulk Data Entry is selected by the NLENRG Subcase Information command. In the following comments, filename implies the actual name of the input file or model.
  2. When NLENRG Bulk/Subcase Entry pair are defined, the energy variables are printed into the filename_e.out file for all implicit nonlinear subcases.
  3. For implicit nonlinear subcases, HyperGraph data file for the global energy variables is named as filename_s<n>_e.nlm for each nonlinear subcase; where, <n> denotes the subcase ID.
    HyperGraph data file for the per-entity energy variables, if activated is named as for each entity in each nonlinear subcase:
    • filename_eset<ID>_s<n>_e.nlm (Element SET-based energy)
    • filename_cont<ID>_s<n>_e.nlm (Contact Interface-based energy)
    • filename_pgap<ID>_s<n>_e.nlm (PGAP Property-based energy)
    Where,
    <ID>
    Denotes the entity ID
    <n>
    Denotes the subcase ID

    The files *.nlm can be read and plotted by HyperGraph and a HyperGraph session file named filename_energy.mvw is created for straightforward plotting of the global energy variables.

    For Explicit nonlinear subcases, the global energy variables are output to a file named filename_s<n>_e.expl for each explicit subcase, where <n> denotes the subcase ID and a HyperGraph session file named filename_expl_energy.mvw is created for straightforward plotting of the global energy variables.

  4. For implicit nonlinear subcase, if NLENRG entry is not defined, the global energy variables are written into a HyperGraph data file (filename_s<n>_e.nlm) for each time increment. However, the output of the filename_e.out file requires the presence of NLENRG Bulk/Subcase Entry pair.
  5. The energy output for both Implicit and Explicit Subcases are listed in the table below.
    Energy Variables Contents of the Energy Variables Implicit Nonlinear Subcases Explicit Nonlinear Subcases
    Internal Energy Total strain energy which includes elastic strain energy, plastic dissipation energy, viscoelastic dissipation energy and damage dissipation energy. Supported Supported
    Plastic Dissipation Energy Energy dissipated by plastic deformation. Supported Supported
    Hourglass Energy Energy dissipated by artificial hourglass control. NA Supported
    Contact Normal Energy Contact constraint energy in normal direction due to penalty constraint enforcement. Unsupported Supported
    Contact Frictional Energy Energy dissipated by contact friction. Unsupported Supported
    Static Stabilization Energy Energy dissipated by artificial static stabilization. Supported NA
    Contact Stabilization Energy Energy dissipated by artificial static contact stabilization. Supported NA
    Kinetic Energy Kinetic energy Unsupported Supported
    Total Energy The sum of Internal energy, Hourglass energy, Contact Normal energy, Contact Frictional energy, Static Stabilization energy, Contact Stabilization energy and Kinetic energy. Unsupported Supported
    External Work External work Unsupported Supported
  6. Implicit nonlinear analysis does not support hourglass elements and so hourglass energy is always zero for implicit subcases.
  7. Energy output for implicit nonlinear analysis is only controlled by the NLENRG Bulk/Subcase Entry pair. There is no influence of NLMON or NLOUT entries on the nonlinear energy output. Additionally, energy is always output on-the-fly dynamically during the analysis.
  8. For Explicit Dynamic Analysis, currently only the FREQ option is supported.
  9. The following table summarizes the energy output files:
    Subcase Types Input Options Energy Output Files Energy Output
    Implicit Nonlinear Subcases Default (no NLENRG Bulk/Subcase pair) filename_s<n>_e.nlm and filename_energy.mvw See Comment 4
    With NLENRG Bulk/Subcase pair filename_s<n>_e.nlm, filename_eset<ID>_s<n>_e.nlm, filename_cont<ID>_s<n>_e.nlm, filename_pgap<ID>_s<n>_e.nlm, filename_e.out and filename_energy.mvw See Comment 2, 3 and 4
    Explicit Nonlinear Subcases Default (no NLENRG Bulk/Subcase pair) filename_s<n>_e.expl and filename_expl_energy.mvw See Comment 2 and 8
    With NLENRG Bulk/Subcase pair filename_s<n>_e.expl and filename_expl_energy.mvw NLENRG for Explicit is only to allow usage of FREQ option. See Comment 2 and 8