Objective Function for sensitivity based shape optimization

Overview

The OBJECTIVE FUNCTION is the function, which value can be maximized or minimized during the optimization. This function depends on the results of the FE analysis. Therefore, the values of interest must be derived from the FE results in order to define an objective function and functional constraints. The results of the FE analysis (total displacement, energy, etc.) for determining the objective function and functional constraints are called ’design responses’. A single value from the design response must be specified for the definition of the objective function using the command DRESP (Design Response).

Objective function terms

SIMULIA Tosca Structure.shape allows optimization on different stress hypotheses, strain formulations and damage results. The most used equivalent stress is von Mises (SIG_MISES).

Static analysis	Description
DISP_ABS DISP_X DISP_Y DISP_Z DISP_X_ABS DISP_Y_ABS DISP_Z_ABS	Displacement design responses
ROT_ABS ROT_X ROT_Y ROT_Z ROT_X_ABS ROT_Y_ABS ROT_Z_ABS	Rotation design responses
STRAIN_ENERGY
INTERNAL_FORCE_ABS INTERNAL_FORCE_X INTERNAL_FORCE_Y INTERNAL_FORCE_Z INTERNAL_FORCE_X_ABS INTERNAL_FORCE_Y_ABS INTERNAL_FORCE_Z_ABS	Internal forces
INTERNAL_MOMENT_X INTERNAL_MOMENT_Y INTERNAL_MOMENT_Z INTERNAL_MOMENT_X_ABS INTERNAL_MOMENT_Y_ABS INTERNAL_MOMENT_Z_ABS	Internal moments
REACTION_FORCE_ABS REACTION_FORCE_X REACTION_FORCE_Y REACTION_FORCE_Z REACTION_FORCE_X_ABS REACTION_FORCE_Y_ABS REACTION_FORCE_Z_ABS	Reaction forces
REACTION_MOMENT_X REACTION_MOMENT_Y REACTION_MOMENT_Z REACTION_MOMENT_X_ABS REACTION_MOMENT_Y_ABS REACTION_MOMENT_Z_ABS	Reaction moments
SIG_MISES	Von Mises Stress
Modal analysis	Description
DYN_FREQ DYN_FREQ_KREISSEL	Dynamic frequency
Analysis independent	Description
VOLUME

Note:

Stress responses (*SIG*) are only supported by Tetrahedron 4 and 10 as well as Hexahedron 8
All stress responses are based on element groups
SIG_* will generate a pseudoload for EACH element