Topology design of additively manufactured CFRP for impact resistance via B-spline-based equivalent static load method

Additive manufacturing (AM) extends the design freedom of continuous fiber-reinforced polymer (CFRP) composites, enabling the fabrication of complex structures with tailored properties. However, it is still challenging of structural topology optimization for impact resistance, due to its inherent nonlinearity. In this work, a B-spline-based Equivalent Static Load (BSESL) method is proposed for impact-resistant designs with low-velocity loading and manufacturability constraints. Pseudo-density and fiber orientation are concurrently optimized and parameterized through B-splines, ensuring smooth fiber orientations without additional filtering due to the high-order continuity of splines. By adjusting the control parameter sizes (CPS) of the B-spline fields, a trade-off between mechanical performance and manufacturability is evaluated. The effectiveness of the proposed method is validated through theoretical design and drop-weight experiments, exhibiting significant improvements in impact resistance and manufacturability.