The Preparation And Investigation Of Carbon Fiber Reinforced Composites Core

In this paper, a carbon fiber reinforced composites core was made by pultrusion, and the conductor was made by twisting aluminum wire outside. The aluminum conductor of carbon fiber reinforced composites core could achieve the transformation of exiting transmission lines and increase transmission capacity. So it was of great economic and social significance to study carbon fiber reinforced composites core and the conductor. Some research was done for the preparation and properties of the composites core and conductor in the paper.Pultrusion process, which consisted of setting of yarm, impregnation of resin, curing and traction, was adjusted. Carbon fiber reinforced composites core was made by pultrusion, whose final curing temperature was 200-220℃and content of curing agent was 40%.The self-made composites core was compared to ACCC made by CTC company. It was shown that the coefficient of thermal expansion of the core was smaller than ACCC, which meant that it was more effective to reduce the sag of conductor. Dynamic mechanical properties of the core were studied by dynamic mechanical analysis. The results show that the capability of resisting deformation of self-made core was greater for its higher storage modulus. The glass transition temperature of self-made core was lower than ACCC by 10℃, which should be improved through the modification of epoxy matrix. The tensile strength of self-made core was great than ACCC. The results of scanning electron microscope show that the matrix bond tightly with fiber without debonding phenomenon.Aging behavior of composites core was explored. It was found that the absorption characteristics of composites core obey the Fick's law at low temperature. When inmmersing in distilled water at 100℃, the absorption behavior agreed with Fick's law at the early stage, while the moisture rate decreased at the later stage. Moreover, the increase of environmental temperature led to a higher equilibrium moisture content and a shorter time to the equilibrium. Heat aging resulted in the decrease in the flexural strength of the composites core, and the higher the environmental temperature, the faster decline in flexural strength decreased, the greater the content. The results of DMA show that the storage modulus decreased with aging time, and loss factor increased with aging time. Infrared spectrometer was employed to study the composites core, it was found that there was no chemical reaction through the aging, only dissolution or precipitation of the uncured epoxy. The results of the SEM show that the interface between the fiber and matrix suffered different degrees of damage, especially in the distilled water at 100℃.Properties of self-made conductor was tested. The apparent quality of the conductor reached the standards, and compared with traditional conductor steel reinforced, the new conductor was ligher with higher tensile strength. There was a sudden change of slope in the stress-strain curve, because the core response in loading and unloading was entirely elastic, while the aluminum undergowent elastic-plastic deformation. The composite core had a much lower coefficient of thermal expansion than aluminum, which caused that the sag of the conductor hardly changed when temperature increased to certain constant. Thus, the new conductor could be used at higher temperature. Capacity of the test results show that the capacity of the new conductor was much more than traditional one, which enabled the expansion of transmission line. Moreover, the new conductor passed the vibration, corona and radio interference test successfully. All results shown that self-made aluminum conductor carbon fiber reinforced composites core was able to achieve the construction design requirements, and was in good condition in field application.