Research On Temperature On Piezoresistivity Of Smart Carbon Fiber Reinforced Polymer(CFRP) Material

The development of intelligent technology gradually penetrates into the field of civil engineering,especially for the structural health monitor(SHM)of important structures and also toward the direction of intelligence.Carbon fiber reinforced polymer(CFRP)has become a research hotspot in the field of Civil Engineering due to its bearing characteristics and intelligent characteristics at the same time,providing realistic preparation for intelligent building,smart building and smart city.Supported by the National Natural Science Foundation of China(No.51478209)named the self.sensing properties of prestressed concrete structures based on CFRP materials and based on the existing theory and research foundation,the relationship between the response of CFRP and ambient temperature mathematical model and the effect of the modified resin matrix of carbon powder and nano-silica on the temperature-resistance effect of the carbon fiber sensor were studied.At the same time,the reliability of the model was verified and the theory and data were provided for reference.The main research contents are as follows:1.Improve the sensing process with CFRP material preparation.According to the special requirements of the sensing element and the existing preparation process,some preparation steps have been adjusted to improve the preparation speed of the laboratory prepared sensing CFRP material and shorten the test period.Provide the train of thought for the future sensing components from laboratory preparation to factory automation production.2.Combine the theory of CFRP and mesomechanics of composite materials,the constitutive relation between resistance(piezoelectric)and temperature change under temperature field is established,the possible phenomena are analyzed,and the application of theory model of CFRP material is expanded It is of great importance to study the coupling of resistance,structural strain field and temperature field of CFRP material.3.Study on the carbon fiber sensing elements of the modified resin matrix.In order to achieve both bearing and smart properties,the experimental reference to the actual operating temperature range(-40?80 ?),CFRP epoxy resin matrix and modified epoxy resin matrix(ie,adding carbon powder and nano-silica particles).After the change of the resistance of the CFRP material with temperature,puting forward suitable for the actual conditions under the matrix mixed with carbon nano-silica particles better mass ratio,the CFRP material temperature resistance model and the existing data analysis to prove the feasibility and reliability of temperature resistance model.It provides a reference for the research and development of intelligent properties of the smart CFRP material temperature in the future,such as mass concrete temperature monitoring and structural self-regulation.