Remarks and Examples

This section shows remarks and examples for DRESP command.

This page discusses:

Remarks

  1. No variables with TYPE FIX are permitted; that is, DRESP is determined using SYSTEM or OPER type.
  2. DRESPs are a special type of VARIABLEs with a limited set of possible types and definition types.
  3. Relative DRESPs can be created by defining two design responses with the same TYPE and DEF_TYPE and with the definition of an OPER design response, which creates the difference in the values of the first two design responses. The node or element groups can only contain one node or element per definition.
  4. In general, only variables of TYPE = DISP_X, DISP_Y, DISP_Z and ROT_X, ROT_Y, ROT_Z and REACTION_FORCE_X, REACTION_FORCE_Y, REACTION_FORCE_Z and REACTION_MOMENT_X, REACTION_MOMENT_Y, REACTION_MOMENT_Z and INTERNAL_FORCE_X, INTERNAL_FORCE_Y, INTERNAL_FORCE_Z and INTERNAL_MOMENT_X, INTERNAL_MOMENT_Y, INTERNAL_MOMENT_Z are admitted for VAR_OPER = SUB, SUB_ABS or COMBINE. For the special case that referenced design responses are of equal type, operator VAR_OPER = SUB also supports DISP_ABS and operator VAR_OPER = SUB_ABS supports DISP_ABS, ROT_ABS, REACTION_FORCE_ABS, REACTION_MOMENT_ABS, INTERNAL_FORCE_ABS and INTERNAL_MOMENT_ABS. For VAR_OPER = KSO, only variables of TYPE = DYN_FREQ and only in context of sensitivity-based topology and sizing optimization are allowed. Absolute displacements are not allowed for combination (COMBINE). Mean values of displacements can be calculated using this option, see example beneath.
  5. Design Responses can only be combined using DEF_TYPE = OPER if they refer to the same group.
  6. For sensitivity-based topology optimization, design responses can only be combined using DEF_TYPE = OPER if they refer to the same load cases. Combination of design responses with OPER cannot be done for two separate load cases.
  7. The parameter VARIABLE can also be used to define operands for VAR_OPER = SUB or SUB_ABS. In this case, only two entries are admitted, weights are not admissible and their order is significant.
  8. For center of gravity and moment of inertia, the reference coordinate system is always interpreted as rectangular (Cartesian) coordinate system. Cylindrical and spherical coordinate systems are not supported.
  9. Plastic strain values (TYPE = STRAIN_PLASTIC) are calculated by Tosca Structure and might differ slightly from your solver results.

Examples

Load case independent:


DRESP
  ID_NAME    = volume
  DEF_TYPE   = SYSTEM
  TYPE       = VOLUME
  GROUP_OPER = SUM
  EL_GROUP   = all_elements
END_

Load case dependent: 


DRESP
  ID_NAME   = first_eign_freq
  DEF_TYPE  = SYSTEM
  TYPE      = DYN_FREQ
  LC_SET    = MODAL,1, ALL
END_

Relative displacement of two nodes:


DRESP
  ID_NAME   = disp_x_first_node
  DEF_TYPE  = SYSTEM
  TYPE      = DISP_X
  LC_SET    = STATIC,1, ALL
  NODE      = 3399
END_

DRESP
  ID_NAME  = disp_x_second_node
  DEF_TYPE = SYSTEM
  TYPE     = DISP_X
  LC_SET   = STATIC,1, ALL
  NODE     = 3398
END_

DRESP
  ID_NAME  = relative_displacement
  DEF_TYPE =  OPER
  VAR_A    = disp_x_first_node
  VAR_B    = disp_x_second_node
  VAR_OPER = SUB_ABS
END_

Mean displacement of two nodes (variable definition see above):


DRESP
  ID_NAME  = mean_displacement
  DEF_TYPE =  OPER
  VARIABLE = disp_x_first_node,0.5
  VARIABLE = disp_x_second_node,0.5
  VAR_OPER = COMBINE
END_