| Prepreg is a composite of resin matrix and reinforcement made by impregnating continuous fibers or fabrics with resin matrix under strictly controlled conditions.It is an intermediate material for manufacturing composite materials.With the continuous progress of research and development of composite materials,the application field is expanding day by day.Different manufacturing processes and working conditions of composite materials also put forward different requirements for prepreg,and the requirements for the performance of prepreg are becoming higher and higher.The prepreg used in this paper is low temperature curing glass fiber reinforced epoxy resin prepreg.The forming process is vacuum bag pressing.Compared with the mechanical properties of original hand pasting,vacuum bag forming and RTM forming,the mechanical properties of the glass fiber prepreg laminates selected in this paper have been improved significantly,and the bending strength of the prepreg products is higher than that of hand pasted glass fiber reinforced plastics.It is 198.93% higher and its bending modulus is 98.78%.Pre-impregnated products have been greatly improved in weight loss,stiffness,strength,dimensional stability and other aspects,and their mechanical properties are much higher than those of the original FRP.Moreover,the failure rate of the product in use is obviously reduced,the reliability of the product is improved,and the life cycle cost(LCC)is saved.Autoclave,Heat Press Forming and Vacuum Bag Only(VBO)are commonly used in the preparation of composites with prepregs.Through the study of the low temperature curing process of prepregs,the low temperature curing epoxy prepreg forming process has been successfully developed.The feasibility of the product has been verified by the trial production of typical products.Finite element analysis shows that the rigidity and strength of the prepreg products are much better than those of the original FRP structures.The deformation displacement of the side wall of the prepreg is reduced by nearly half,the deformation displacement of the door column cover is reduced to one third of the original,and the structure of the prepreg has more safety margin.From the analysis results,the safety factor of the products of the two materials is higher than that of EN12663.Safety factor S1 and S2,structural safety;with deformation as the evaluation criterion,the deformation of prepreg products is less than that of FRP products,and the strength of prepreg is better than that of FRP products.Through the layer design,the mechanical properties of the original FRP structure can be obtained under the service condition,which meets the requirements of safe and reliable use,and at the same time,the weight loss effect is not less than 30%.The development of trial production process,laying design principle,process configuration and step demonstration is carried out.The batch production analysis is carried out to find out the process difficulties,find out the reasons and put forward the solving measures.The bonding performance between prepreg and metal parts was tested at room temperature.The test results show that the bonding effect of MA830 is relatively good,and the failure mode meets the requirements.In addition,the fire protection performance of the prepreg products is excellent,which can reach the highest HL3 level of EN45545-2 R1,and meet the requirements of the standard TB/T 3139-2006.Through the research of production technology,the batch production of products has been realized.Although the cost of products made with prepreg is higher than that of original paste,RTM and vacuum bag film forming,it has good workability,remarkable weight reduction effect,improved product quality,reduced the occurrence of faults and maintenance costs. |
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