Lateral crashworthiness performance of CFRP/aluminum circular tubes with mesoscopic hybrid design

Thin-walled fiber-reinforced plastic (FRP)/metal hybrid tubes exhibit superior crashworthy performance, which have shown promising prospect as collision-proof components to withstand lateral collisions. In the present work, novel hybrid tubes with alternated stacked FRP and aluminum layers hybridized at the mesoscopic scale were proposed. The lateral crashworthiness characteristics of carbon-fiber-reinforced plastic (CFRP)/aluminum hybrid circular tubes were investigated based on analytical, experimental and numerical method. To explore the effects of material composition on deformation patterns and energy absorption efficiencies, quasi-static lateral compressive tests were carried out and the results were compared. Under lateral compression, the CFRP/Al hybrid tubes were crushed progressively and stably. Large amounts of energy were absorbed through the progressive failure of the fiber and plastic bending of aluminum layers. Compared to pristine CFRP counterparts, the specific energy absorption (SEA) and crushing force efficiency (CFE) of CFRP/Al hybrid tubes increased by 45.58% and 73.68%, respectively. The peak crushing force (PCF) of CFRP/Al tubes was reduced by more than half when compared to pure CFRP tubes. Compared to experimental results, the numerical models predicted the crushing behavior and crashworthy performance with high accuracy. Additionally, an analytical model of CFRP/Al tubes was established to predict the energy absorption characteristics and the predict outcomes agreed well with the experimental results. The FRP/Al mesoscopic hybrid structures exhibited superior deformation stability and satisfactory energy absorption performance under lateral loading, overcoming the limitations of lightweight FRP materials for lateral collision protection. In sum, these findings look promising for lightweight anti-collision structural design.