Study On Temperature Field In Resin Curing Stage For Fiber Reinforced Composites By VARTM Process

Fiber-reinforced resin matrix composite materials are made of reinforcing material and resin material by relating molding process. They have relatively excellent overall performance. The temperature is one of the main factors that affect product quality and production efficiency in curing process of resin matrix composite materials. Different parts of temperature distribution and variation will influence the curing process of composite materials, which affect the performance and quality of composites in the end. Moreover, the temperature fields are affected by molding material and resin matrix composite materials. Thus it is an issue of concern for businesses and manufacturers to understand and improve the temperature fields distribution of composite molding process. The reasonable temperature distribution can improve the quality and performance of the products.In this paper, simulations and experiments of curing temperature in fiber-reinforced resin matrix composites with R688 Epoxy resin、H3268 Curing agent and biaxial glass fiber are explored. The purpose is to provide theoretical foundation for improving product quality. The main research achievements of the whole paper are summarized as follow:First of all, resin different heating flowing curves in different heating rate with the DSC testing are obtained. According to the relationship of heat flow rate, curing reaction rate and degree of cure are calculated. The curing factors(for example reaction order activity energy and Pre-exponential factor) in the Kissinger and Crane equation are solved. Finally the cured kinetic equation with those parameters is calculated.Then, based on the thermal conduct and curing kinetics theory, physical and mathematical model of composite materials curing process is built by using the finite element method in this paper. According to epoxy curing kinetics equation parameters, curing kinetics equation source term is written with C language. It is embedded in the database to connect the fluent by the UDF compilation. The composite curing exothermic and temperature changes during curing process can be simulated with FLUENT.At last, It is got on measuring experiments the temperature field of curing process in VARTM technology. Experiment of monitoring curing temperature field by using the process of VARTM with R688 Epoxy resin as substrate and glass fiber as strengthen material is performed. Temperature change in different time and different position of composite materials is recorded by collecting the thermocouples embedded into the glass fiber to some of point by using the temperature recorder.