Strain-sensing Characteristic Research Of Polymer Based Carbon Fiber Smart Layer

With support of NSFC(National Natural Science Foundation of China) Funding:smart concrete and its structure(program No:50238040) and the multi-field coupling mechanism and field diagnosis of carbon fiber smart layer (program No:10672128),aiming at healthy monitoring of large structure,we designed the polymer based carbon fiber smart layer to sense the deformation and damage,meanwhile made explorative theoretical analysis and experimental researching.The primary work we did are as follows:1.Through uniaxial tension and cyclic loading experiment of carbon fiber felt, researched the deformation-resistance character,obtaining the strain intelligent degree and sensitive limit and the resistance change law under cycle deformation by the experiment results.On the basis of conductive channel theory,analyzed the mechanism of the deformation-resistance character of carbon fiber felt.2.For polymer based carbon fiber smart layer,systemic research of deformation-resistance character was carried out.laying carbon fiber felt in the epoxy resin to generate the polymer based carbon fiber smart layer,as a strain sensor.Through uniaxial tension and cyclic loading experiment,we checked about the intelligent degree,linearity,repetition,creep,and stability and so on.By a lot of experimental data obtained,evaluated the static sensing characteristic of polymer based carbon fiber smart layer.3.By testing the longtime resistances under different temperature,and resistances under cyclic static and dynamic load,we researched sensing stability of polymer based carbon fiber smart layer.Through the experiment result,we obtained the zero stability under different temperature and intelligent degree stability under cyclic static and dynamic load of polymer based carbon fiber smart layer.The five layer carbon fiber felt polymer based smart layer had the relatively most perfect zero stability and intelligent degree stability,so that it suit to inspect the strain of structure. But its intelligent degree stability still needed improve. 4.Application of polymer based carbon fiber smart layer:pasted the polymer based carbon fiber smart layer on the surface of FRP plate with surface crack.Tested the resistance of smart layer change with the surface crack change by flexural failure experiment,in order to establish the measurable surface crack change scale and the crack change -resistance relationship in that scale.Tested the resistance of smart layer change with the surface crack change in the measurable scale by flexural cycle experiment,Simulated the FRP plate with the polymer based carbon fiber smart layer pasted on the surface under cycle bending by ANSYS,in order to verify the trustworthiness of experiment result.