Forward Design Method of CFRP Bumper With Variable Cross‐Sections and Variable‐Thickness Lamination: From Topology Design to Parametric Design

ABSTRACT The anisotropy of CFRP and the flexibility of lamination schemes pose major challenges for component design. This study introduces a forward design method for a CFRP automotive bumper, treating the structural cross‐section as the macro design variable and the lamination scheme as the meso variable. To address the complexity of anisotropic components, the CFRP laminate constitutive model was simplified using classical laminate theory, establishing a foundation for the conceptual design of variable cross‐sections and thickness partitions. Building on this, a dual‐scale parametric framework was further developed, integrating macro and meso parameters through a non‐uniform rational B‐spline (NURBS) with a custom parametrization scheme. Prototypes manufactured using this method were experimentally tested. The results demonstrate that, compared with a benchmark CFRP bumper designed by conventional empirical methods that directly replicate metal counterparts, the proposed approach enables forward design, achieving a 22.2% weight reduction, a 22.9% increase in energy absorption, and a 12.7% decrease in peak impact force.