Conceptualization design and analysis of lightweight composite rims for a formula student race car with a review of existing concepts

Overview

This work presents a structured methodology for designing lightweight carbon fiber reinforced polymer rims for an electric Formula Student race car. The contribution consolidates a systematic review of existing composite rim concepts with an integrated design approach that decouples laminate sizing from geometric constraints and accommodates manufacturing and vehicle integration requirements within typical Formula Student resource parameters.

Methods and approach

The design process encompasses three primary phases: a structured review of existing CFRP rim and wheel concepts from Formula Student and automotive applications to establish the reference frame; concept development and comparative evaluation of three candidate designs (hybrid composite-aluminum rim, full composite spoke rim, and full composite flange rim); and iterative finite element analysis to establish laminate architecture meeting strength and stiffness criteria. The final design employs a symmetric stacking sequence of woven carbon fiber fabric with alternating 0° and 45° plies. Manufacturing feasibility was integrated through enhanced numerical simulation incorporating realistic ply draping behavior, informing tooling design and layup specifications. Load cases representative of Formula Student competition requirements were evaluated, including cornering, acceleration, and braking scenarios.

Results

The selected hybrid configuration with aluminum center disk and composite rim structure achieved a symmetric eight-ply laminate governed by displacement limits under cornering load. The design demonstrated safety factors of approximately 1.5 in compression and 1.8 in tension across all relevant Formula Student load cases. Weight reduction of 49 percent relative to aluminum reference specification was attained, corresponding to a 50 percent reduction in polar mass moment of inertia and 3 percent vehicle mass reduction. The design satisfied camber-angle stiffness requirements and maintained appropriate dynamic response margins under fatigue loading.

Implications

The 49 percent mass reduction and associated reduction in rotational inertia are expected to yield measurable performance improvements in acceleration, braking response, and ride quality characteristics for the vehicle. The methodology provides a transferable framework for composite rim design that integrates laminate optimization with manufacturing process constraints and vehicle-level integration requirements, addressing a gap in prior work that typically isolates geometric or material selection decisions.