Thermal Decomposition Mechanism And Combustion Characteristics Of Typical Aircraft Cargo Compartment Lining Materials

In recent years,the frequency of fire accidents in the cargo compartment of civil aviation transport aircraft has been relatively high.In order to leave enough time for the crew to deal with the fire in the cargo compartment of the aircraft,the civil aviation industry standard MH/T6086-2012 stipulates that the burn-through time is≥5 min.Aircraft cargo compartment lining materials are generally resin-based fiber-reinforced composite materials,which undergo a pyrolysis process before combustion.Therefore,this paper selects a certain type of aircraft cargo compartment lining composite product and prepreg as the research object,uses thermogravimetric analyzer to study the effect of heating rate on its pyrolysis process,and uses Kissinger,Flynn-Wall-Ozawa method to calculate the activation energy judgment thermal stability of the material.In addition,the influence of thermal radiation intensity and material thickness on the combustion characteristics of glass fiber prepreg was studied by cone calorimeter,and a model was established by AHP,and its fire risk was comprehensively evaluated.The main research conclusions are as follows:(1)The larger the heating rate,the higher the overall pyrolysis temperature of the aircraft cargo compartment lining composite material.There are two pyrolysis stages at each heating rate,and the pyrolysis peaks increase from 202℃to 232℃and 601℃to 673℃respectively.The apparent activation energy determines that the material has strong thermal stability in the second stage.(2)The heat radiation intensity increases,the ignition time decreases,the heat release rate,the total heat release amount,the mass loss rate,the carbon monoxide rate advance and the peak value increases,indicating that the greater the heat radiation intensity,the better the fire comprehensiveness of the material.the greater the danger.(3)The materialδ=0.22 mm,δ=0.65 mm,δ=1.03 mm andδ=1.45 mm were burned through at 17 s,78 s,238 s and 486 s respectively,andδ=1.85 mm did not burn through at 15min,the thickness increased,the longer the delamination time is,the more obvious the honeycomb carbon layer on the backfire surface.The heat radiation is the same,the heat release rate,mass loss rate,carbon monoxide rate,total heat release and total smoke are positively correlated with the thickness of the material,and a prediction model for the ignition time of the materialδ=1.85 mm is given.Judging the fire hazard of the material,it is concluded that under the thermal radiation intensity of 25-35 k W/m~2,the fire risk evaluation index of the material withδ=1.85 mm is the smallest;under the thermal radiation intensity of 40-50 k W/m~2,the material withδ=1.45 mm the fire risk evaluation index is the smallest,and the risk is smaller.