Study On Damping Property Of Contineous Carbon Fiber Reinforced Epoxy Composites Filled With Carbon Nanotube

Multi-scale fiber reinforce composite filled with carbon nanotube (CNT) is attractive for the high strength, damping and corrosion resistance, that can be utilized in civil engineering to control the structural vibration, especially for bridge stay cable. Motivated by applying this multi-scale fiber reinforced composite (CNT-CFRP) in stay cable, the damping property is studied in way of theoretical modeling together with experimental characterizing. The achievements of this paper will improve the understand of damping of CNT-CFRP and the optimizing methods will be developed, which can promote the application of CNT-CFRP in stay cable and other civil engineering field. To reach the above mentioned objects, following works were done:1) Damping model is established based on micro-mechanics. Nanocomposite material is a multi-body complex system and dynamic energy dissipation comes from multiple sources. The originations of damping are considered to be interfacial friction dissipation between CNT and polymer, CNT induced strain concentration and the own damping of polymer. Based on the proposed model, the damping of composite and these damping originations was linked, which can explain the effects of CNT concentration, aspect ratio and orientation on damping.2) CNT filled polymer as two-phase composite is fabricated. The tensile strength and dynamic damping properties of this composite are measured with Materials Testing System (MTS) and Dynamic Mechanical Analyzer (DMA), respectively. The testing apparatus for obtaining mechanical properties of composites are set up and measurement procedures are given. In particular, mechanical properties of composites are measured for the specimens with different CNT volume concentration, experimental results show that CNT additive can provide the composite with higher damping and tensile strength properties.3) CNT filled resin as tow-phase composites and CFRP laminates using CNT filled resin as three-phase composites are fabricated and tested with the same method to two phase composite, the testing apparatus for obtaining mechanical properties of composites are set up and measurement procedures are given. In particular, mechanical properties of composites are measured for the specimens with different CNT volume concentration, experimental results show that CNT additive can provide the composite with higher damping and tensile strength properties.4) In this research, the effect of orientation and alignment of CNT embedded in an epoxy polymer matrix under a magnetic field on the mechanical properties of the nanocomposite is probed. The experimental results show that the changes in orientation and alignment of CNT depend on the magnetic strength, and the mechanical properties of composites are superior to those that are not exposed to a magnetic field.