3D Printing with Topology Optimization: A Case Study

3D Printing combined with topology optimization made this robot arm joint lightweight and strong.

Introduction

3D printing with topology optimization is revolutionizing how engineers design and manufacture lightweight, high-strength components. By combining computational design algorithms with additive manufacturing, companies can reduce material usage, improve performance, and accelerate development cycles. In this case study, we explore the topology optimization process, analyze real-world applications, and discuss how tariffs on imported metals and printer hardware influence the adoption of this technology in both plastic and metal 3D printing.

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Understanding the 3D printing with the Topology Optimization Process

Topology optimization is a mathematical approach that determines the best material layout within a given design space, subject to loads, boundary conditions, and performance objectives. The most common method, Solid Isotropic Material with Penalization (SIMP), iteratively removes low-stress material to converge on an optimal geometry. Designers begin with a fully solid volume in finite element analysis (FEA) software, apply constraints such as maximum displacement or natural frequency targets, and let the algorithm identify areas where material can be eliminated without compromising structural integrity. This can then be used with 3D printing to accurate recreate the complex designs.

Integrating Topology Optimization into Additive Manufacturing Workflows

Implementing topology optimization effectively requires a tight integration of design, simulation, and manufacturing steps. As part of a robust additive manufacturing workflow, engineers should:

1. Establish a Digital Thread: Create a seamless data pipeline from CAD modeling to Finite Element Analysis (FEA) and then to the slicing software. This digital thread ensures that design intent, simulation results, and manufacturing constraints are all synchronized.

2. Define Clear Objectives and Constraints: Before running optimization algorithms, specify performance goals such as minimum stiffness, maximum natural frequency, or targeted stress distribution. Also define manufacturing constraints—minimum feature size, overhang angles, and support structure limitations—to avoid unprintable geometries.

3. Select Appropriate Optimization Software: Tools like Altair Inspire, ANSYS Topology Optimization, or SolidWorks Generative Design offer built‑in features for additive manufacturing. These platforms can incorporate AM‑specific settings, such as print orientation and layer height, directly into the optimization routine.

4. Iterate with Prototypes: Use low‑cost plastic prints (PLA, PETG) for initial validation of optimized geometries. Early physical testing identifies practical issues—such as unsupported spans or surface variability—allowing teams to refine the design before committing to metal printing.

5. Plan for Additive and Subtractive Hybrid Processes: Some optimized parts benefit from post‑printing machining or surface finishing. Include machining allowances in the design phase and schedule secondary operations such as drilling, milling, or shot peening to meet tight tolerances and surface finish requirements.

6. Leverage Lattice Structures for Lightweighting: Advanced optimization can incorporate graded lattice infills or topology‑driven internal channels for cooling or fluid flow, unlocking performance gains in weight‑sensitive applications.

7. Measure and Validate: After printing, conduct mechanical testing—such as tensile, fatigue, and modal analysis—to compare real‑world behavior against simulated results. Use these insights to calibrate material models and improve future optimization runs.

By embedding topology optimization within the additive manufacturing workflow—aligned with rigorous validation and hybrid process planning—organizations can fully exploit the design freedom and performance advantages of 3D printing.

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Case Study 1: Airbus A350 Cabin Bracket

Image Source: https://www.researchgate.net/figure/Cabin-bracket-for-the-Airbus-A350-XWB-showing-the-original-part-and-topology-optimised_fig3_328036589

One of the most celebrated examples of topology optimization in additive manufacturing is the Airbus A350 XWB cabin bracket. Originally, this bracket was an assembly of more than 30 individual sheet‑metal parts and fasteners. Using a SIMP‑based algorithm and boundary conditions defined by mounting interfaces and load cases, Sogeti High Tech reduced the component to a single, consolidated part printed in AlSi10Mg aluminum alloy via EOS laser powder bed fusion. The optimized design achieved a 55 percent weight reduction compared to the baseline assembly, while satisfying all fatigue, static and certification requirements for aviation use. By eliminating rivets and complex welds, the new bracket also reduced installation time and met stringent aerospace quality standards.

Case Study 2: BMW i8 Roadster Roof Bracket

Image Source: BMW

In the automotive sector, BMW Group pioneered production series use of a topology‑optimized 3D printed metal component for the i8 Roadster. Engineers applied generative design software to define load paths and minimize material, producing a roof‑bracket fixture that is 44 percent lighter and ten times stiffer than its conventionally manufactured counterpart. Printed in 316L stainless steel using Selective Laser Melting, the bracket required no support structures thanks to integrated lattice supports and careful build‑orientation rules. BMW now mass‑produces over 600 of these brackets per print run, demonstrating how topology optimization coupled with additive manufacturing can deliver performance, cost and assembly benefits at scale.

A medical device company applied topology optimization to design a PLA-based cranial implant with patient-specific geometry. Using SIMP in a generative design tool, the optimized implant reduced volume by 35 percent and improved stress distribution under physiological loads. The part was printed on a plastic 3D printer and then sterilized for surgical use. Clinical testing confirmed a precise fit and improved load transfer, illustrating the synergy between topology optimization and biocompatible materials.

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Advantages in Plastic and Metal Printing

SLS 3D Print Product - Image Source: https://sinterit.com/blog/sls-technology/what-is-sls-3d-printing/

Topology-optimized designs often feature complex internal lattices and organic shapes that traditional manufacturing cannot produce. Additive manufacturing excels at producing these geometries:

• Plastic 3D Printing: Fused Deposition Modeling (FDM) enables rapid prototyping of optimized designs in materials like PLA, PETG, and ABS, with layer heights as low as 0.1 mm to preserve fine features.

• Metal 3D Printing: Processes such as SLM and Electron Beam Melting (EBM) allow direct fabrication of optimized metal parts in titanium, nickel alloys, and stainless steel, achieving near-full density and fine resolution for critical aerospace and medical applications.

Best Practices for Implementation

To successfully leverage topology optimization in 3D printing, teams should:

1. Integrate Design and Simulation: Use CAD and FEA tools to define loads and constraints upfront. Ensure mesh density supports accurate stress analysis.

2. Consider AM Constraints: Apply build orientation, overhang limitations, and minimum feature size constraints during optimization to avoid unsupported geometries.

3. Plan Post-Processing: Account for heat treatment, surface finishing, and machining allowances when tolerances are critical.

4. Validate Prototypes: Perform mechanical testing—such as tensile, fatigue, and biomechanical tests—to confirm performance against simulated predictions.

   
   

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Conclusion

3D printing with topology optimization offers a powerful pathway to create lightweight, high-performance parts that were previously unattainable. Despite challenges from tariffs on imported materials, the combination of algorithm-driven design and additive manufacturing can yield significant cost savings, material efficiency, and product innovation . Michigan Prototyping Solutions is dedicated to guiding clients through topology-optimized workflows, ensuring structural integrity and manufacturability for both plastic and metal components. By harnessing the latest in optimization software and in-house 3D printing capabilities, we help turn complex design goals into reality.

Sources

1. Mat. Ind. Spr. constraint in TO for AM: topology optimization methods (Math. Ind.)(mathematicsinindustry.springeropen.com)

2. Full review on TO for metal AM (Taylor & Francis)(tandfonline.com)

3. Sciencedirect case study on SLM bracket mass reduction(sciencedirect.com)

4. ASME Proc. Laser Powder Bed Fusion case study(asmedigitalcollection.asme.org)

5. IEOM Detroit topology optimization impact study(ieomsociety.org)