Design Responses (DRESP)

Load Case Dependent Design Responses

The general syntax for the LC_SET item in the DRESP command is

LC_SET = <approach>, <loadcase>, <substep>, <shell_layer>.

For Abaqus users, substep refers to the increment of a nonlinear analysis. Substep does not refer to the load case number in an Abaqus step with multiple load cases.

Solver Sensitivities

For an overview about all design response types for which load case can provide sensitivities, refer to Allowed Optimization Strategy for Design Responses.

User Subroutine Design Responses

User-defined design responses allow the user to provide element-based design response values and sensitivity values through Abaqus user subroutines. Multiple user design responses can be calculated with a single subroutine. The design responses might be based on either stress or plastic strain. This could be applied for example to calculate laminate failure criteria etc. The user must provide Tosca with the name of the design response and the base type that are used in the subroutine:

DRESP
  ID_NAME           = STRESS_BASED_USER_DRESP
  DEF_TYPE          = SYSTEM
  TYPE              = USER_DRESP
  USER_DRESP_ID     = S11_DRESP
  USER_DRESP_OUTPUT = S
  EL_GROUP          = ALL_ELEMENTS
END_

DRESP
  ID_NAME           = PLASTIC_STRAIN_BASED_USER_DRESP
  DEF_TYPE          = SYSTEM
  TYPE              = USER_DRESP
  USER_DRESP_ID     = PE_DRESP
  USER_DRESP_OUTPUT = PE
  EL_GROUP          = ALL_ELEMENTS
END_

in the above examples, USER_DRESP_OUTPUT takes a value equivalent to the Abaqus identifier of the base quantity. This can be either S or PE. USER_DRESP_ID is the value of the dresp_id parameter in the user subroutine. For more information on how to write subroutines for calculating the design response values, see UELEMDRESP section in the Abaqus documentation.