• Schuh, Benjamin
• Bachmann, Jens
• Roese-Koerner, Imke
• Wierach, Peter

Abstract

The presented study deals with the optimization of fire properties of CFRP fuselage materials in a"pool-fire" scenario (a kerosene fire underneath an aircraft on ground) with the aim to increase thetime until the structure fails. For this purpose hybrid material systems are being developed where theflame retardant is directly incorporated into the material. In this way, weight can be saved and thepeeling effect, which is common for finishes, would be prevented. Due to the very high heat fluxduring a kerosene fire, powdered additives and layers are introduced into the composite, which form athermal barrier or a barrier for gases in case of fire and protect the underlying structure from theeffects of the flames. Of these materials, the fire behaviour with regard to smoke density and smoketoxicity is determined. The results show a significant reduction of smoke density for most of the testedmaterials and comply with the limits of toxic gases for cabin material systems. For a realistic relevellingof the “pool-fire” scenario, a test facility with a propane torch was build, which creates a heatflux of 180kW/m². In this test, the specimens are exposed to flames for 4min and the temperatureprofile at their backside is recorded with a thermocouple. In order to investigate the mechanicaldamage of the materials trough the fire, additional specimen were exposed to flame for 15s and theremaining compressive strength was determined. It was found that in particular a titanium foil underthe top layer can contribute significantly to improvements in the mechanical properties as well as toslow down the temperature rise on the back of the material.

Topics

• density
• impedance spectroscopy
• polymer
• Carbon
• strength
• composite
• titanium