Maximize a certain mode

Sometimes it may be sufficient to only have interest for one single mode and at the same time we do not want to regard the other modes. This can be done using mode tracking.

DRESP
 ID_NAME = dresp_eig2
 DEF_TYPE = SYSTEM
 TYPE = DYN_FREQ
 LC_SET = Modal,All,2
END_

OBJ_FUNC
 ID_NAME = max_ dresp_eig2
 DRESP = dresp_eig2
 TARGET = MAX
END_

OPTIMIZE
 ID_NAME  = opt
 DV = my_design_nodes
 STRATEGY  = BEAD_SENSITIVITY
 OBJ_FUNC = max_ dresp_eig2
END_

OPT_PARAM
 ID_NAME  = my_parameters
 OPTIMIZE = opt
 MODETRACKING = ON
 MODENUMBERS = 10
END_

The second mode is chosen to be maximized. The important difference is that mode tracking is activated in the optimization parameters (MODETRACKING= ON). The default for mode tracking in SIMULIA Tosca Structure is to take 5 modes into account, but this can be changed with the item MODENUMBERS. This should not be set too high because of computational effort.



Optimization displacements and convergence plots without (a) and with (b) mode tracking