Numerical Simulation And Experimental Study On Curing Process Of Resin-based Composites With Blow Dryer

Resin-based composites have advantages such as low specific gravity,high specific strength and modulus,good fatigue resistance,and good chemical stability.Now they are playing an increasingly important role in the aviation industry.In addition to the properties of the material itself,the curing process has a great impact on the properties of the resin-based composite material.In this paper,a resin-based composite material using epoxy resin as the matrix and glass fiber as the reinforcing material is taken as the research object.Numerical simulation and experimental research are performed on the curing process with the blow dryer.(1)DSC experiment is performed on the epoxy resin and curing agent mixed in proportion.The curing kinetic parameters of the resin were obtained from the experimental data,and the curing process temperature curve was obtained to provide parameters for establishing the physical model and mathematical model of the thermal curing process.(2)Physical and mathematical models based on thermal convection,heat conduction,turbulent motion,and curing kinetics are established for resin-based composite materials cured by the blow dryer.A finite element calculation method of temperature field and thermal stress field during the curing process of composite laminates is constructed.(3)Finite element models of air domains are constructed with different inlet and outlet sizes,a blow dryer curing experimental platform is established,and the reliability of the model in combination with experiments is verified.The influence of inlet and outlet dimensions on the curing process of laminate is studied by finite element methods.The conclusions are as follows: the larger the inlet and outlet dimensions of the air area are,the more intense the turbulent motion is.The temperature rise of the laminate become faster,but the temperature gradient and thermal stress change little.(4)The finite element models of the air domain designed at different exit positions are constructed,and the influence of the exit position on the curing process of the laminate by the blow dryer is studied.The conclusions are as follows: When the exit position is located in the middle and lower part of the exit section,the temperature gradient and thermal stress of the laminate during the heating stage are reduced.(5)Temperature and thermal stress fields of resin-based composite laminates cured by a blow dryer with different ply thicknesses are analyzed numerically.The conclusions are as follows: the thickness of the laminate is inversely related to the temperature gradient and thermal stress of the node,and the temperature distribution of the laminated plate with a greater thickness is more uniform.(6)The effects of different curing processes on the curing process of laminates are numerically analyzed.The conclusions are as follows: The temperature value,heating rate,temperature gradient and thermal stress value of laminates cured by the blow dryer are lower than laminates cured by the heat blanket.However,the difference in residual thermal stress between the two is little.The research results optimize the curing technology of the resin-based composite with the blow dryer and provide a parameter basis for the curing of repair patches using the blow dryer in China.