Self-sensing Carbon Nanofiber/Epoxy Resin Matrix Composites And Their Application

Carbon nanofibers (CNF) has excellent physical properties and electrical properties as the reinforced material of epoxy resin. Carbon nanofibers reinforced epoxy resin composite materials can effectively improve the mechanical properties and conductive performance of epoxy resin, also the composite material possess stable and sensitive performance. Using piezoresistivity of Carbon nanofibers epoxy resin matrix composites made of sensors, can be effective for health monitoring of structures. This paper aims at using piezoresistivity of carbon nanofibers reinforced epoxy resin matrix composite to monitor the force and deformation of structures and has carried out a series of experimental study.(1)In this paper, Based on the experimental research, created a method to disperse carbon nanofibers into epoxy resin using organic solvent ultrasonic, Can effectively dispersed carbon nanofibers into the epoxy resin matrix.(2)The axial compression experiment was carried out with different content of CNF composites, to explore the change of compression performance of different CNF content composites. Draw the influence on compressive strength, elastic modulus, poisson’s ratio of compositrs after adding CNF.(3)The sensor of composite material electrode material, electrode arrangement and resistivity measurement method are discussed in this paper. This paper compared the difference of composite’s electrical performance and the pressure sensitive performance tested by two electrode method or four electrode method. And analyzed the conductive percolation behavior of the composites.(4)This paper analysis of the piezoresistivity of carbon nanofibers epoxy resin matrix composites under the uniaxial compression test, the cyclic loading test and the increase cyclic loading test, And analyzed the mechanism of piezoresistivity.(5)Then considered the temperature and humidity effect on the properties of conductive composite materials. To temperature cycling test, this paper discusses the relationship of composite strain and the change of resistance in the process of temperature change; Based on the research of the relationship of Water absorption and resistance of the composites change, this paper studied the influence of humidity factors on the the properties of conductive of composite materials. (6)Finally, the carbon nanofibers epoxy resin matrix composites are prepared into sensor, applied to monitoring the stress and strain of concrete column.