Study On Damping Of Structural Resin Based Composite Materials Toughenedby Polyamide Nonwoven Fabric

Based on the "EX-situ" toughening enhancement technology between composite material layer, the dissertation aims to design a woven fabric toughened composite laminated plate, the damping performance obtained improvement while maintaining its maximum static mechanical properties and improving its fracture toughness.In order to maximize the mechanical properties of the composites, it needs base resin to have a good throughout all laminates. Based on this, this paper chooses Polyamide woven with high porosity and not dissolving in epoxy as intercalation materials, further more. For further improve the damping performance of materials. The paper also explores on the surface of PNF load with piezoelectric effect and low glass transition temperature crystalline thermoplastic PVDF (poly vinylidene fluoride) effect on structural damping properties.The above two kinds of intercalation materials of epoxy resin matrix composite laminate was prepared in this paper，We studied the effects of intercalated layers of laminated plates’ dynamic mechanical performance, vibration, bending property, inter laminar shear strength and fracture toughness. The results show that: Intercalated materials can significantly improve the laminated damping performance and toughness, along with increased insertion layer, the loss factor of composite laminates increased. And, in a dynamic thermodynamic curve is only one of the mechanical loss peak，the storage modulus decreases with the increase of the number of inserted layer, the glass transition temperature decreased with the increase of the number of inserted layer; Under the condition of normal temperature, insert the7layer PNF laminates, the loss factor (beta) compared with the blank sample is increased by1.52times, the load of PVDF loss factor of composite laminates increased1.75times, basically unchanged the static mechanical properties. In terms of the fracture toughness, composite material into the PNF type I (GIC) and type II (GIIC) delamination fracture toughness were increased1.88times and4.38times, insert load PVDF’s PNF laminates’ GIC increased5.6times, GIIC increased3.94times, illustrate the load PVDF’s PNF intercalated with significant toughening effect; Finally, through the specimen cross section SEM analyses its toughening mechanism. Through the ANSYS software for the insertion of different layers PNF laminates’ free vibration and resonance behavior is simulated by finite element method, determine its vibration attenuation curve and the first-order vertical bending natural frequency, the simulation results agreed well with experimental results, verify the accuracy of the simulation.In summary, using PNF or PVDF load PNF intercalated laminated plate can greatly improve the laminated damping performance and toughness, and the basic mechanical property, it also can meet the requirements of heat resistance. This study on the structural damping material’s development has certain promote significance.