Phase 1: Reference Design Synthesis (FreeSize Optimization)
In freesize optimization, the thickness of each designable element is defined as a design variable. Applying this concept to the design of composites implies that the design variables are the thickness of each Superply (total designable thickness of a ply orientation) per element.
 Objective
 Minimize the weighted compliance of the two load cases.
 Constraints
 Volume fraction < 0.3
 Design Variables
 Element thicknesses of each ply orientation.
 Manufacturing Constraints
 Ply percentage for the 0s no more than 80% exist.
Launch HyperMesh and Set the OptiStruct User Profile
Import the Model
Set Up the Optimization
Create Freesize Optimization Design Variables
Create Optimization Responses
 From the Analysis page, click optimization.
 Click Responses.

Create the volume fraction response.
 In the responses= field, enter Volfrac.
 Below response type, select volumefrac.
 Set regional selection to total and no regionid.
 Click create.

Create the weighted component response.
 In the responses= field, enter wcomp.
 Below response type, select weighted comp.
 Click loadsteps, then select all loadsteps.
 Change the weighting factors for gravity and pressure to 1.0.
 Click return.
 Click create.
 Click return to go back to the Optimization panel.
Create Design Constraints
 Click the dconstraints panel.
 In the constraint= field, enter con_vol.
 Click response = and select volfrac.
 Check the box next to upper bound, then enter 0.3.
 Click create.
 Click return to go back to the Optimization panel.
Define the Objective Function
 Click the objective panel.
 Verify that min is selected.
 Click response= and select wcomp.
 Click create.
 Click return twice to exit the Optimization panel.
Define the Output Request
Run the Optimization
 fairing_freesize.out
 OptiStruct output file containing specific information on the file setup, the setup of the optimization problem, estimates for the amount of RAM and disk space required for the run, information for all optimization iterations, and compute time information. Review this file for warnings and errors that are flagged from processing the fairing_freesize.fem file.
 fairing_freesize_des.h3d
 HyperView binary results file that contain optimization results.
 fairing_freesize_s#.h3d
 HyperView binary results file that contains from linear static analysis, and so on.
 fairing_freesize_sizing.*.fem
 A plybased sizing optimization input file generated during freesizing phase. This resulting deck contains PCOMPP, STACK, PLY, and SET cards describing the plybased composite model, as well as DCOMP, DESVAR, and DVPREL cards defining the optimization data. The * sign represents the final iteration number.
 fairing_freesize_sizing.*.inc
 An ASCII include file contains the same plybased modeling and optimization data as in the input deck. The * sign represents the final iteration number.