Distance-dependent thermal response of Nano-modified Aluminium-GFRP fiber metal laminates: A comparative experimental study

Fiber metal laminates (FMLs) enhanced with nanofillers have been explored for thermal management in the automotive and aerospace applications; however, their thermal behavior as a function of distance remains inadequately investigated. This study evaluated the thermal barrier efficacy of aluminium–glass fiber-reinforced polymer (GFRP) fiber metal laminates modified with titanium dioxide (TiO 2 ) nanoparticles, graphene nanoplatelets (GNPs), and silica (SiO 2 ) nanoparticles at heat source distances of 15, 20, and 30 cm. A full factorial design (four materials × three distances × three replicates; n = 36) was implemented with controlled convective heating using a 1000 W hot-air dryer for 10 s. The transient thermal response was assessed using the temperature increase, heating rate, and cooling rate. The TiO 2 -modified laminate exhibited the lowest temperature increase at 15 cm (0.70 ± 0.03°C), representing a 63% reduction compared to the unfilled control ( p < 0.001; Cohen’s d = 60.34). Conversely, GNP-modified laminates displayed non-monotonic distance-dependent behavior, with temperature increase rising from 2.40°C at 15 cm to 2.90°C at 20 cm, and then decreasing to 1.40°C at 30 cm. Two-way analysis of variance (ANOVA) indicated significant effects of material, distance, and their interaction ( p < 0.001), showing a clear coupling between the material composition and heat source proximity. The anomalous graphene response warrants microstructural investigation. TiO 2 recorded the most consistent performance across all distances. This work systematically quantifies coupled material–distance interaction effects in nano-modified FMLs, establishing that nanofiller selection and standoff distance must be jointly considered in thermal barrier design.