Lateral crashworthiness of Al/CFRP hybrid filament-wound Tubes: Meso-Scale modeling based on 3D yarn reconstruction

Lightweight thin-walled structures reinforced by filament-wound CFRP offer excellent lateral crashworthiness while meeting lightweight design requirements for aerospace and related applications. Owing to the complex stacked architecture resulting from winding paths, conventional testing methods are limited in capturing damage mechanisms. Consequently, a 3D winding path planning method was developed suited for complex rotational mandrels based on discrete surface meshes, enabling the construction of a fully 3D Al/CFRP numerical model that captures the mesoscopic yarn architecture with high fidelity. The lateral crashworthiness of Al/CFRP hybrid tubes was evaluated through quasi-static lateral compression experiments and finite element modeling. Results indicate that the Al/CFRP tubes exhibit stable failure behavior due to the plastic deformation of the Al liner, leading to improved energy absorption. Specifically, the mean crushing force and crushing force efficiency increased by 57.14 % and 100 %, respectively, compared to pure CFRP tubes, while the peak crushing force decreased by 41.5 % and 22.9 % compared to pure aluminum and CFRP tubes, respectively. FEM analysis reveals that under lateral compression, interface failure in Al/CFRP tubes exhibits significant spatial delay: damage initiates in the diagonal (≈45°) symmetric regions of the tube wall, while delayed failure occurs at the four symmetric positions along the loading and horizontal axes due to the formation of plastic hinges. In the winding composite layers, tensile failure of both fiber and matrix occurs in the outer regions near the non-loaded end, while the inner layers exhibit brittle matrix cracking. Overall, these findings offer valuable insights for the design of lightweight crashworthy structures.