Tec de Monterrey, 2022

The industry is shifting from internal combustion to electric vehicles, and Metalsa (Mexican manufacturer of structural automotive steel parts) required a redesign of its Battery Housing (the enclosure that holds and protects EV batteries).

The original design used aluminum, which is lightweight but costly and mechanically weaker than steel. Metalsa’s challenge was to develop a steel version of the housing that: 

​

Maintains critical dimensions (for compatibility with Jaguar I-PACE EV), increases weight by no more than 15% relative to aluminum design, withstands dynamic loads between 600–1200 MPa, impact tests of 5–8 g, and an operating temperature range −28 °C to 50 °C, and resists corrosion, fire, and mechanical damage while ensuring hermetic sealing and manufacturability with Metalsa’s existing stamping, rolling, and pressing processes.

​

The project began with the generation of design alternatives through brainstorming sessions, functional decomposition, and the use of morphological matrices. From the outset, the focus was on balancing performance, manufacturability, and weight, which guided the team to apply DFMA (Design for Manufacturing and Assembly) and Reduction of Parts (RP) analyses. These tools were crucial in simplifying the assembly and identifying components that could be consolidated or removed to improve efficiency.

​

Material selection was another key stage, carried out using Granta EduPack to evaluate over 600 possible candidates. After progressively narrowing the options based on mechanical strength, corrosion resistance, manufacturability, and cost, the team selected 22MnB5 high-strength steel as the most suitable material for the housing. This decision reflected the need to achieve higher strength than aluminum while remaining compatible with Metalsa’s existing manufacturing processes.

​

With the material chosen, the redesign of the housing proceeded through iterative modeling and simulation. The original aluminum design was first analyzed with static and dynamic FEA using SolidWorks, ANSYS, and Fusion 360.

These simulations revealed areas of high stress concentration and confirmed that a straightforward material substitution would result in excessive weight. To address this, the team reduced wall thicknesses to approximately 1.2 mm, introduced transverse beams to improve load distribution, and redesigned cross-sections to optimize stiffness-to-weight ratio. Topology optimization tools were then used to remove unnecessary material from structural beams, and several components were combined to reduce assembly time and complexity.

​

The redesigned model was validated digitally through multiple analyses. Static simulations showed minimal deformation, less than 0.1 mm, under expected loading. Impact simulations at 30 mph revealed localized plastic deformation, which, rather than compromising safety, acted as an energy-absorbing mechanism similar to a crash fuse. Modal analysis demonstrated that the first natural frequency occurred at 65 Hz, well above the 50 Hz safety threshold, confirming the structure’s resistance to harmful resonant vibrations. Finally, updated DFMA evaluations showed significant reductions in assembly time compared to the original design, reinforcing the benefits of part consolidation and simplification.

​

The final redesign of the battery housing achieved significant progress toward Metalsa’s goals, though it also highlighted areas for further refinement. By replacing the original aluminum with 22MnB5 high-strength steel, the team delivered a structurally robust prototype capable of meeting safety and performance requirements. The redesigned housing weighed 121 kilograms, which represented a 24% increase over the aluminum version and exceeded the 15% target. Despite this penalty, the prototype demonstrated clear advantages in durability, manufacturability, and crash energy absorption.

Simulation results confirmed the effectiveness of the redesign. Under static loading, the housing showed no signs of critical stress or deformation, validating its ability to withstand everyday operational forces. Dynamic impact analyses revealed small regions of plastic deformation, but these behaved as intended energy absorbers, reducing the severity of impact forces transmitted to the occupants. Modal analysis further demonstrated the structural integrity of the design by showing natural frequencies well above critical resonance thresholds.

Beyond mechanical performance, the project also delivered tangible improvements in manufacturability and efficiency. Through part consolidation, optimized cross-sections, and the introduction of transverse beams, the redesign reduced assembly time and material usage. These improvements not only lower potential production costs but also simplify maintenance and serviceability. Importantly, the housing was validated as compatible with Metalsa’s existing processes—rolling, stamping, and pressing—ensuring industrial feasibility without the need for costly new equipment.

Although the weight target was not fully met, the project laid a strong foundation for future iterations. The team proposed potential solutions such as hybrid designs combining steel with aluminum in selected components, or the application of advanced topology optimization to further remove non-critical material. Both approaches could bring the design closer to the desired weight while preserving strength and manufacturability.

​​

Please find attached below the relevant documents to this project. (Note: most, if not all documents, are in Spanish)