Deformation Prediction Of Microwave Cured Carbon Fiber Reinforced Polymer Composites

Compared to the autoclave curing of composites,the microwave curing of composites has the advantages of short manufacturing time and low energy consumption.However,the microwave cured composites have the same problem as the thermally cured samples,which is the deformation of composite part.Associated with the Natural Science Foundation project and the demand from the aerospace industry,this paper studied the deformation mechanism of the microwave cured carbon fiber reinforced polymer composites and the corresponding predicting modeling.The main achievements of this paper are listed as follow:(1)The deformation mechanism of microwave cured carbon fiber reinforced polymer composites was studied.The effects of the chemical shrinkage of polymer,the tool-part interaction and the mismatch between the thermal expansion coefficients(CTE)of carbon fiber and polymer were investigated to research the deformation mechanism of microwave cured composite parts.The chemical shrinkage-induced linear strain in the polymer was systematically measured by an improved device.Experimental results indicated that the chemical shrinkage of several epoxy resins(with amine curing agent)were significantly reduced by microwave curing,compared with thermally cured samples.A reduction mechanism was proposed that it can be ascribed to the low hydrogen bond content in microwave cured samples.(2)A deformation prediction model of microwave cured composites was established.In order to precisely acquire the tool-part interaction,a continuous comprehensive friction coefficient between composite and tool was calculated.The tool-part interaction analysis model was mainly studied.Moreover,the other three analysis models(the temperature field analysis model of microwave cured composites,the analysis model of chemical shrinkage and the analysis model of the mismatch of CTE of carbon fiber and polymer)were built.Based on those analysis models,the deformation of microwave cured composite part can be calculated.(3)Some experiments had been conducted to verify the deformation predict results of the model.Compared to the experimental results of the composites' deformation,the simulation accuracy can be markedly improved by applying the continuous comprehensive friction coefficient.The simulation errors for those composites cured by C-shaped toughened glass mould,C-shaped composite mould and L-shaped toughened glass mould were 18.1%,7.7% and 31.7% respectively,and reduced to 8.7%,5.3% and 10.1%.