Example 8: Topology Design with Casting Fabrication Constraints

Use the model lever_arm.prt for this example.

Description

This example demonstrates how to use topology optimization to design a light and stiff structure.

Highlighted features

Min Strain Energy, Mass Fraction constraint, Filling (casting) fabrication constraint

Optimization problem statement

The following optimization problem will be created and solved:

• Objective:

◦ Minimize Strain Energy

When the objective is to minimize strain energy, the purpose is to get the stiffest structure under the given load for the allowable amount of material.

• Subject to:

◦ Mass fraction <= 0.2

Analysis

The example contains one analysis. The loads/constraints are shown in the image below:

Mesh control

Maximum element size: 15 mm

Topology region

• References:

The component, excluding volume region 1 and 2, as shown in the image below.

• Init. mass fraction: 0.2

When mass fraction is used as a constraint, it is recommended to use the same constraint bound value as the initial mass fraction value.

• Fabrication constraints:

◦ Filling along the Z axis of coordinate system WCS

◦ Minimum member size: 30 mm

It is recommended to set the Minimum member size to at least twice that of the mesh element size.

◦ Spread fraction: 0.5

Design objective

Minimize Strain Energy

Design constraints

Mass fraction <= 0.2

Optimization study

The study refers to the defined topology region, design objectives, and constraints

Advanced settings:

• For analysis output files, only the first and last cycle are requested.

• Use default settings for all other analysis and design parameters.

Topology Result

• Topology density isosurface

• Topology element density

Geometry Reconstruction

• Tessellated model

• Solid model