Sandwich panels combining metallic cores and fibre-reinforced polymer skins are gaining increasing interest in lightweight design due to their high specific stiffness and impact-energy absorption. This study investigates novel hybrid aluminium honeycomb sandwich (AHS) panels featuring basalt fibre-reinforced polyamide 12 skins manufactured from industrial polyamide 12 (PA12) waste powder. The composite skins were adhesively bonded to commercial AA5754/AA5052 AHS panels using a polyurethane adhesive, and their mechanical behaviour was assessed through quasi-static perforation and low-velocity impact tests using a hemispherical indenter. Hybridisation significantly increased the panel stiffness (+33% for d3 and + 27% for d6 vs. AHS), while impact tests showed higher peak loads and specific energy absorption (SEA). For the d6 configuration, BFRP/AHS panels exhibited up to 46% higher SEA than flax-based hybrids and 6% higher than GFRP-reinforced sandwiches at comparable impact energies (≈180–200 J). Radiographic and thermographic inspections confirmed more distributed collapse mechanisms in the 6 mm cell core, explaining its superior energy-absorption performance. These findings demonstrate that BFRP hybridisation enhances crashworthiness with minimal mass increase, while enabling the reuse of PA12 waste. The developed panels offer a promising, sustainable solution for lightweight, impact-resistant structures in transport and protective applications.
Sustainable hybrid sandwich structures: quasi-static and low-velocity impact response of BFRP/AHS panels
Pietro Russo;
2026
Abstract
Sandwich panels combining metallic cores and fibre-reinforced polymer skins are gaining increasing interest in lightweight design due to their high specific stiffness and impact-energy absorption. This study investigates novel hybrid aluminium honeycomb sandwich (AHS) panels featuring basalt fibre-reinforced polyamide 12 skins manufactured from industrial polyamide 12 (PA12) waste powder. The composite skins were adhesively bonded to commercial AA5754/AA5052 AHS panels using a polyurethane adhesive, and their mechanical behaviour was assessed through quasi-static perforation and low-velocity impact tests using a hemispherical indenter. Hybridisation significantly increased the panel stiffness (+33% for d3 and + 27% for d6 vs. AHS), while impact tests showed higher peak loads and specific energy absorption (SEA). For the d6 configuration, BFRP/AHS panels exhibited up to 46% higher SEA than flax-based hybrids and 6% higher than GFRP-reinforced sandwiches at comparable impact energies (≈180–200 J). Radiographic and thermographic inspections confirmed more distributed collapse mechanisms in the 6 mm cell core, explaining its superior energy-absorption performance. These findings demonstrate that BFRP hybridisation enhances crashworthiness with minimal mass increase, while enabling the reuse of PA12 waste. The developed panels offer a promising, sustainable solution for lightweight, impact-resistant structures in transport and protective applications.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
