Research On The Electromechanical Properties Of Carbon Fiber Composites

In recent years, more and more requirement was paid to the conductive polymer composite materials with the rapid development of information technology and the electron industry . The conductive composites are light, cheap, easy to shape. They can adjust their conductive property to satisfy the different needs. They are mass production. So studying conductive composites is becoming a hot point. At the same time, the resistance is changed when the load is different. So the study of its dynamic detecting, self-diagnose, advance alarm is also becoming a hot topic by using its smart property.In this dissertation, the study on conductive property and electromechanical behavior of conductive composites has reviewed. Not only the conductive property of carbon fibers reinforced vinyl resin composites which has different content of carbon fibers , fiber aspect ratio and surface of carbon fiber treated by thick nitric acid, but also the relation between the strain of the static state and dynamic cycle load and the volume resistance of the short chopped carbon fibers, short chopped carbon mat, unidirectional carbon fibers reinforced vinyl resin composites have been which is based on a plenty of experiments.The results of the analysis and experiment show that the electrical resistivity of the short chopped carbon fibers reinforced the vinyl ester resin composites is nonlinear decline with the incremental of the short chopped carbon fibers and appears the phenomenon of percolation; The fiber aspect ratio affects the electrical resistivity of the short chopped carbon fibers reinforced the vinyl ester resin composites and the electrical resistivity is nonlinear decline with the incremental of the fiber aspect ratio; The result also indicated that the surface morphology of carbon fibers were rougher and the grooves on fibers and the grooves were wider and deeper and the amount of oxygen functional group is increased after treated by thick nitric acid. The electrical resistivity of the treated short chopped carbon fibers reinforced the vinyl ester resin composites is larger than that of the untreated short chopped carbon fibers reinforced the vinyl ester resin composites and the phenomenon is gradually subdued. The corresponding relations between the strain of the static state and dynamic cycle load and the volume resistance of the short chopped carbon fibers, short chopped carbon mat, unidirectional carbon fibers reinforced vinyl resin composites is existed. The physical modes of these kinds of composites are also designed based on the experiment data. The resistance and strain of the short chopped fibers reinforced vinyl composites satisfy the equation of y =A + Bx + Cx~2 in the static strain test method and the short chopped mat reinforced vinyl composites' is y = A + Bx. By the above studies , as a smart material, it is possible to the carbon fiber reinforced vinyl resin composites to be dynamic detected, diagnosed, alarmed by itself.