Numerical Simulation And Experimental Study On Curing Process Of Thermosetting Resin Matrix Composite

Resin matrix composites have been widely used in various industries due to their excellent properties such as high specific strength and modulus,good fatigue resistance and so on.In addition to the properties of the material,the curing process and the repairing process also have a great influence on the properties of the composites.Therefore,according to the actual needs of the components,the optimal design of the composite repair technology and curing process can be carried out by changing the curing process and the repairing process.In this paper,using the two kinds of heat curing methods,including the traditional heating method and heat curing instrument designed by the new electric heating curing method,the thermal curing process of 3234/T300 B thermosetting resin matrix composites was studied by numerical simulation and experimental research,and the main contents are as follows:(1)The physical model of composite patch thermal curing and the mathematical model based on the heat conduction and curing kinetics were established,and the finite element methods for calculation of temperature field and stress field during the thermal curing process of thermosetting resin matrix composite patch was constructed.(2)The temperature curve of thermal curing process by heat-blanket,the temperature field and stress field were numerical analyzed for different warming rate thermal resin composite patch rate under the condition of the stress field,the conclusions are as follows: the faster the warming rate,the temperature gradients within the patch and internal thermal stress increases with the warming rate;the curing rate is faster.(3)The temperature field and stress field were numerical analyzed for different cooling rate thermal resin composite patch rate under the condition of the stress field,the conclusions are as follows: the faster the cooling rate,the temperature gradients within the patch and internal thermal stress increases with the cooling rate;the lower the cooling rate the thermal residual stress of composite laminates is small.(4)The finite element model for the curing process of composite patches with different scarf angle was constructed.The impact of scarf angle on the temperature and stress field of resin matrix patch during the thermal curing process were numerical analyzed,the conclusions are as follows: in the center point,the scarf angle increases,the peak temperature and curing rate,thermal stress decreasel;in non center point,although there is no peak,but the temperature fluctuations will appears.At the same time,the scarf angle is bigger,the curing rate decreases and the thermal stress increases with increasing scarf angle.(5)The finite element model for the curing process of composite patches with different stacking methods was constructed.The influence of stacking sequence on the curing process of resin matrix composite patch,the conclusions are as follows: the symmetrical ply composite materials can effectively reduce the thermal stress and residual thermal stress;the reparing patch should be stacked with the same orientation with the motherboard,so as to minimize thermal stress and optimize the quality of repair materials.(6)The curing technology based on Joule heating is studied,and the experimental platform is designed.The characteristic parameters of the electric heating method and the traditional heating method were studied by the experimental and numerical simulation methods.The temperature field and thermal stress of these two curing methods were compared.The results of this study provide a good experimental and numerical basis for the repair of composite materials.