Fire Reaction Properties Of Carbon/Epoxy Composites

Carbon/epoxy composites have been widely used in the aerospace field.Carbon/epoxy laminate,foam-core sandwich composite and carbon/epoxy sandwich composite are the most commonly used laminate and sandwich structure materials in the aircraft industry.However,the flammability of epoxy resins and foam core material is an inherent hazard,and carbon fibre also can produce toxicity gas under high temperature and pressure.To study the thermal behavior and fire reaction properties of carbon/epoxy composites,a comprehensive experimental investigation and theoretical analysis were carried out in this work using thermo-gravimetric analysis,cone calorimeter,smoke chamber,vertical/horizontal burning tests,limiting oxygen index and scanning electron microscope tests.First,the effect of ply scheme on fire reaction,flame spread and smoke properties of carbon/epoxy laminate was studied.It has been found that the thickness of composite have a certain effect on above all properties of carbon/epoxy laminate,and the ply scheme obviously affects the smoke properties,and has no effect on fire reaction and flame spread properties.Then,the effect of forming process on thermal behavior,fire reaction and post-fire properties of carbon/epoxy sandwich composite was studied.Several typical characteristic parameters were obtained and analyzed.Several thermal and fire reaction properties were evaluated,and typical pyrolysis kinetic and fire dynamic parameters were also determined.The ignition time model,thermal behavior model,mass loss rate model and heat release rate model were obtained.Additionally,it has been found that carbon/epoxy laminates formed using autoclave forming process have better thermal and fire properties,but this forming process negatively affects the post-fire mechanical property of carbon/epoxy laminates.Finally,the smoke risk and hazard of three type carbon/epoxy composites was assessed,and three new parameters are proposed for smoke hazard assessment by analytic hierarchy process.It has been found that the smoke hazard of carbon/epoxy composite under flaming condition is higher than that under smoldering,the combustion condition have significantly effect on smoke properties of carbon/epoxy composite.The result shows that the smoke hazard of foam-core sandwich composite is the highest.