Symmetrical Optimization - Bridge

Training:

You can find all relevant data for this tutorial in the Example folder!

CAD Preparation: To use the symmetry function, the model must be centered in the coordinate origin along the symmetry plane.

Step 1: Create a new project

In a first step, you need to create a new project. All data (geometry and configuration) directly will be copied and saved in a new project-folder, located in your workspace:

• Start MSC Apex Generative Design 2019
  
• Create a new project using the symbol

• Enter a projectname and save the project
• Open the newly created project

Step 2: Model generation

• Upload all relevant stl files by clicking on the symbol in the objects/surfaces area
• Select all stl files 
• The field at the bottom shows notifications and makes you aware of missing input

• The uploaded objects are listed in the objects/surfaces area

• Assign a Material to each object/surface and enter the specific values for the Young's Modulus (210e3) and poisson ratio (0.28) in the Material Editor

• Activate the option design space for the relevant stl file. Only one volume can be selected as such:

Step 3: Definition of boundary conditions

Go to the boundary conditions tab to enter the loads and fixations as follows. For each boundary condition a name, a space and the specification of the boundary condition is entered as follows:

• Object "Bridgestreet1" experiences a force of 4000 N in y-direction (Force). The force of the whole bridge is 16.000 N. If you are using the symmetry option, the force must be adjusted to the calculation model. If only a quarter of the component is calculated (symmetry along the x and z axis), the force must also be quartered. The example already considers this restriction.

• A total of 1 force and 4 fixations should have been created as a result

All boundary conditions must be assigned to the load case. The number of load cases can be changed using the "+" or "-" characters. The assignment of the boundaries to the load cases can be made in the boundary conditions or load cases area by selecting the different boundary conditions while the load case is activated.

• Active in Loadcase1: Force, Fixation1, Fixation2, Fixation3 and Fixation4

Step 4: Definition of optimization parameters

Switch to the optimization area. You can find more information about the parameter selection here.

• Choose the design type normal
• Enter the optimization goal stress: 50 MPa
• Set the symmetry settings: YZ-Plane and XY-Plane

• Open Result File Formats. The following result files should be activated:
  • stl File: results of each iteration in stl file format
  • stl Files Intersected: result of each iteration intersected with the design space in stl file format
  • ply Files with Stress: results with the information of stresses of each iteration (must be activated to show the results in the Visualization space)
  • ply Files with Displacement: results with the information of displacements of each iteration (must be activated to show the results in the Visualization space)
  • More information on result file formats here

All Inputs can be viewed and checked in the configuration file. The file should look like this.

Please make sure only one .amendate file is in your project folder.

• You can always change the design type, stress and solverMaxMemory to influence the results and try out different options. You can find further information here.

Step 5: Save the project

Step 6: Starting the optimization and visualizing the results

If all data are correct, the optimization can be started and tracked in the results area.

All result iterations are displayed as soon as they are available. The progress of the optimization can also be monitored via the AMendate log file. Furtheremore you are able to stop the optimization in this selection area. A restart however is not possible.

The warning "The following component is not considered in this iteration" is to be ignored in case of the symmetry constraint. Due to the symmetry, only a part of the component is used for the calculation and therefore only a part of the objects is used. The objects that are not considered are listed in the warning.

The optimization is finished after 64 iterations (optimizationtype: optimizing).

Step 7: Visualization of Stresses

The legend can be influenced using the slider. The function "Automatically set to local minimum and maximum" considers the stresses of each iteration and sets the values from the current iteration.

Step 8: Visualization of Displacements

The legend can be influenced using the slider. The function "Automatically set to local minimum and maximum" considers the displacements of each iteration and sets the values from the current iteration.

You might also be interested in these tutorials:

• Introductory Optimization - Jet-Engine-Bracket
• Introductory Optimization - Eccentric
• Introductory Optimization - Pedal
• Introductory Optimization - Hook