Case Study: Redesigning an Automotive Suspension Bracket with Generative Design

In the highly competitive automotive supply chain, weight reduction is a constant mandate. Every gram saved translates to improved fuel efficiency or increased battery range. However, this weight reduction cannot come at the expense of structural integrity or manufacturability.

This case study examines how a mid-sized Tier-2 automotive supplier successfully implemented generative design to redesign a critical suspension bracket, achieving a 22% weight reduction while meeting all performance and manufacturing constraints.

The Challenge

The component in question was a cast aluminum control arm bracket. The existing design was robust but heavy, relying on traditional ribbing and thick cross-sections to handle the complex, multi-directional loads experienced during cornering and braking.

The engineering team was tasked with reducing the weight by at least 15% without increasing the manufacturing cost or changing the existing casting process.

The Traditional Approach vs. Generative Design

Historically, the team would have approached this problem using topology optimization. They would take the existing CAD model, apply the loads, and let the software remove material. The result would be a "bony" structure that an engineer would then have to manually interpret and redraw into a castable shape. This process was iterative, time-consuming, and often resulted in sub-optimal designs.

Instead, the team decided to pilot a generative design workflow using Autodesk Fusion 360.

The Generative Workflow

The shift to generative design required a change in mindset. Instead of modeling the part, the engineers had to model the problem.

1. Defining the Preserve and Obstacle Geometries

The first step was defining the "preserve regions"—the areas where the bracket had to interface with the chassis and the control arm. These included the mounting holes and the bearing surfaces.

Next, they defined the "obstacle regions"—the areas where material could not exist due to clearance requirements for other components, tools, or the suspension's range of motion.

2. Applying Loads and Constraints

The team imported the load cases from their vehicle dynamics simulations. This included maximum braking force, maximum cornering force, and a combined fatigue load case. They also applied the necessary boundary conditions to the mounting points.

3. Setting Manufacturing Constraints

This was the critical step that differentiated generative design from traditional topology optimization. The team specified that the final part must be manufacturable via die casting. They defined the pull direction and the minimum draft angle.

They also specified the material properties of the specific aluminum alloy they were using.

4. Generating and Evaluating Options

The software generated over 40 different design iterations, exploring various load paths and structural strategies. The team used the software's filtering tools to narrow down the options based on mass, maximum stress, and factor of safety.

They selected three promising candidates and exported them as solid CAD models.

Validation and Results

The selected designs were not just "dumb" meshes; they were editable CAD geometry. The team imported these models into their standard FEA package (Ansys) for rigorous validation against the original load cases.

The winning design looked significantly different from the original bracket. It featured organic, sweeping curves that efficiently distributed the stress across the entire volume of the part.

The Final Metrics:

• Original Weight: 1.45 kg
• New Weight: 1.13 kg
• Weight Reduction: 22%
• Factor of Safety: Maintained at 1.5x
• Manufacturing: Fully compatible with existing die-casting tooling (minor modifications required).

The Corporate Takeaway

The success of this project wasn't just about the software; it was about the workflow. By defining the manufacturing constraints upfront, the generative design tool produced a part that was actually usable, not just a theoretical concept.

For mechanical engineers in corporate environments, the lesson is clear: Generative design is no longer a research project. When applied correctly, with a strong understanding of the underlying physics and manufacturing realities, it is a powerful tool for achieving significant engineering advantages.