Boundary Condition Sets

To create boundary condition sets

  1. On the Command Panel, click on FEA BCs and then Set.
  2. Click on the Create action button.
  3. Specify the settings for ID/Name.
  4. Enter in the appropriate settings.
  5. Optionally select Specify Analysis Type and/or Specify Modal Max Frequency and enter the appropriate settings.
  6. Click Apply.

Create bcset [id] [name <'name'>] [After bcset <id>] [{Add|Remove} {bc_type}  <id-range | <with name 'name'> >] [analysistype {STATIC|heat|dynamic|modal}] [modal_max_frequency <value>]

To modify boundary condition sets

  1. On the Command Panel, click on FEA BCs and then Set.
  2. Click on the Modify action button.
  3. Enter in the appropriate settings.
  4. Optionally select Specify Analysis Type and enter the appropriate settings.
  5. Click Apply.

Modify bcset {id_list|'name'|all} [name <'name'>] [After bcset <id>] [{Add|Remove} {bc_type}  <id-range | <with name 'name'> >] [analysistype {STATIC|heat|dynamic|modal}]

*** ABAQUS Parameters ***

Modify bcset {id_list|'name'|all} [max_step_increments <value>]     [nonlinear_geometry <on|OFF>][perturbation <on|OFF>][stabilize <on|OFF>]  [steadystate <on|OFF>][modal_max_frequency <value>]

Modify bcset {id_list|'name'|all} [initial_step_size <value>]     [step_period <value>][min_step_size <value>]  [max_step_size <value>][min_step_temperature_change <value>]

Modify bcset {id_list|'name'|all} [mass_scaling <on|OFF>]   [mass_scaling_dt <value>][mass_scaling_factor <value>]     [mass_scaling_type <'uniform'|'BELOW_MIN'|'set_equal_dt'>]

Modify bcset {id_list|'name'|all} [restart <on|OFF>][restart_overlay <on|OFF>]  [{restart_frequency|restart_num_intervals} <value>]

Modify bcset {id_list|'name'|all} [output_field <on|OFF>]     [output_field_frequency <value>] [output_history <on|OFF>]     [output_history_frequency <value>]

Modify bcset {id_list|'name'|all} [el_file <on|OFF>][el_file_frequency <value>]  [node_file <on|OFF>][node_file_frequency <value>]

Modify bcset {id_list|'name'|all} [el_print <on|OFF>][el_print_frequency <value>]  [node_print <on|OFF>][node_print_frequency <value>]

*** NASTRAN Parameters ***

Modify bcset {id_list|'name'|all}  {displacement_output <on|OFF> {PLOT|print|punch|punchprint} {group <ALL|none|<id>> }}

Modify bcset {id_list|'name'|all} {oload <on|OFF> {PLOT|print|punch|punchprint} {group <ALL|none|<id>> }}

Modify bcset {id_list|'name'|all} {mpcforces <on|OFF> {PLOT|print|punch|punchprint}  {group <ALL|none|<id>> }}

Modify bcset {id_list|'name'|all}  {spcforces <on|OFF> {PLOT|print|punch|punchprint}  {group <ALL|none|<id>> }}

Modify bcset {id_list|'name'|all}  {stress <on|OFF> {PLOT|print|punch|punchprint} {group <ALL|none|<id>> }     {CENTER|cubic|sgage|corner} {VONMISES|maxs}}

Modify bcset {id_list|'name'|all}  {element_strain_energy <on|OFF> {PLOT|print|punch|punchprint}  {group <ALL|none|<id>> } {AVERAGE|amplitude|peak}}

Trelis can create BC sets, which is a group of previously defined loads, restraints and contact pairs.  A BCSet is used to define a load case (analysis step) when writing out 3rd party analysis decks.  A BCSet can be a static analysis set, a thermal analysis set, a modal analysis set, or a dynamic analysis set by specifying the analysistype. The After keyword can be used to define the order that the BCSets will be written when the model is exported.

Several solver-specific parameters can be set for a BCSet.  For ABAQUS, parameters associated with *STEP, *STATIC, *DYNAMIC, *FREQUENCY, *HEAT TRANSFER, *MASS SCALING, *RESTART, *OUTPUT, *EL FILE, *NODE FILE, *EL PRINT, and *NODE PRINT can be modified.  For Nastran, output requests can be defined for Displacement, Reaction Loads, MPC Forces, SPC Forces, Stress, and Element Strain Energy.