Study On Curing Process Of Carbon Fiber Reinforced Epoxy Resin Matrix Composite And Optimization Of Compression Moulding Process Parameters

As an important structural material with advantages of high modulus,high specific strength and fatigue corrosion resistance,carbon fiber reinforced epoxy resin matrix composites have been widely used in the aviation industry.A series of complex physical and chemical changes that occur during the curing reaction of resin-based composites have a great impact on the quality and mechanical properties of its molded parts.In this paper,a thermochemical-elasticity multi-field coupling model is created based on the solidification theory of resin-based composites.On the premise that the parameters of the thermophysical and mechanical properties of the composite material change with time and temperature,numerical simulation calculations are carried out on the examples in the literature to verify the correctness of the created model.At the same time,the specific development and evolution process of temperature,curing degree,residual stress and strain in the curing process are analyzed.Using different CHILE models to calculate the residual stress,and found that the model mainly affects the change of the internal stress in the second heating section.The AS4/3501 composite thin-layer laminate model matching the actual compression molding was created,and the effects of two important curing process parameters（cooling rate and holding time）on the curing temperature,curing degree,residual stress and curing deformation were analyzed.The two process parameters of AS4/3501 composites solidification cooling rate and holding time are optimized design:stepwise cooling in the cooling rate range of 2-3 K.min^-1can reduce the temperature gradient,residual stress in the cooling section of the molded part and control the warpage deformation of the laminate;at the same time,when the 1.75 h holding time is selected to complete the curing,it can effectively reduce the curing time cost under the premise of less increase in residual stress.Finally,AS4/3501 composite laminates were prepared by compression molding process and tested for mechanical properties to verify the correctness of numerical simulation predictions from the perspective of composite mechanical properties.