Loads and Boundary Conditions

Within this section some remarks concerning loads and boundary conditions are summarized.

Contact Boundary Conditions

Contact conditions are permitted in the analysis model for topology and shape optimization. Defining a contact surface directly on the edge of the design space is allowed in topology optimization. The shape optimization algorithm has to be inverted (see command OPT_PARAM, parameter SCALE) if the design edge belongs to a contact surface in shape optimization. Convergence difficulties in the FE analysis may arise in cases of complex contact problems due to large changes in the model during optimization. The Use of Contact Boundary Condition Requires a SIMULIA Tosca Structure.nonlinear License

Node Restrictions for Shape Optimization

Node fixations are not loaded during the loading of the analysis model. The boundary conditions (SPC = NR1 and SPC = NR2) are transferred to the optimization model by entering the command

OPTION
 READ_BC = ALL
END_

Node fixations are created in ANSYS® in the load files (*.sxx) of the analysis model with the command:

D, NODE, Lab, VALUE, VALUE2, NEND, NINC, Lab2, Lab3, Lab4, Lab5, Lab6

We recommend considering all fixed node during the reading of the model with the command:

READ_OPTION, SPC, ON