The challenge

The project focused on developing an automated layup optimization process for a composite bicycle frame, starting from an existing finite element model and material characterization data provided by the customer.
The objective was to minimize the overall structural mass while satisfying a series of stiffness and comfort requirements evaluated through representative load cases. These included steering head stiffness, bottom bracket stiffness under different pedaling load configurations, and a dedicated vertical loading condition used to assess rider comfort.
From an optimization perspective, a free-size optimization approach was adopted, allowing the solver to determine the optimal local laminate thickness distribution. Separate design variables were assigned to woven fabric plies and unidirectional plies, while allowable fiber orientations included 0°, 90°, ±22°, and ±45°.
To ensure that the optimization results could be translated into a realistic laminate design, manufacturing constraints were introduced. These included a maximum laminate thickness limit and, in a second optimization strategy, a minimum thickness constraint, preventing mathematically optimal yet impractical solutions.

Our contribution

SmartCAE managed the complete optimization workflow, beginning with a thorough review of the finite element model and the stiffness evaluation criteria associated with each loading condition.
We defined the optimization design regions, distinguishing the primary structural areas from those excluded from optimization, and established a consistent set of design variables for the different ply types and fiber orientations. This enabled the generation of clear and comparable laminate thickness maps.
Two free-size optimization strategies were then executed while incorporating laminate manufacturing constraints and carefully monitoring the numerical stability of the optimization process.
Once the analyses were completed, SmartCAE interpreted the results from an engineering perspective, demonstrating how the optimal distribution of fiber orientations and local reinforcements evolves according to the applied constraints. The resulting thickness maps were transformed into practical laminate design recommendations suitable for manufacturing, with particular attention given to the critical areas governing both global stiffness and local structural response.

Benefits for the client

This approach enabled the customer to make objective, data-driven engineering decisions while significantly reducing the trial-and-error iterations that typically characterize composite product development.
Having access to an optimized reference solution, together with a clear understanding of where structural material is actually required, which reinforcement type is most effective, and which fiber orientations best support the different loading conditions, accelerates convergence toward the final laminate design while maintaining control over both structural performance and manufacturability.
Constraint-driven optimization also identifies meaningful weight reduction opportunities without compromising the stiffness required by functional testing or introducing unrealistic manufacturing solutions. At the same time, it highlights engineering sensitivities and trade-offs—such as the balance between structural stiffness and rider comfort—well before physical prototypes are produced.
By combining advanced simulation, performance-driven engineering, and manufacturing constraints, SmartCAE helps customers reduce technical risk, shorten development time, minimize redesign costs, and deliver composite structures that are both highly optimized and ready for efficient industrial production.