Papers by Keyword: Carbon Fiber Composites

Abstract: At the time of unprecedented development of digital technologies, business owners across various industries need to stay up-to-date in terms of using cutting-edge technologies such as Industry 4.0 to ensure competitive performance. There are still many areas where their positive implications of digital technologies have not been applied. For example, the end-of-life (EoL) waste from the automotive, aerospace, and wind energy industries is still accumulating in landfills. At present, an increasing number of vehicles, airplanes, and wind turbine blades are made of Carbon Fiber Reinforced Polymer Composites (CFRPs) leading to an urgent demand for implementing sustainable waste disposal strategies. Thus, recycling CFRPs is a key research area that provides a potential for improvement, particularly, in terms of digitalization. This study addresses the issues prevalent in this sphere and proposes Industry 4.0 related technologies to be integrated into the CFRP recycling supply chain stages, including waste collection, dismantling, transportation, recycling, and re-manufacturing. For this purpose, key technologies were selected from the literature review, smart recycling trends were defined and relevant analysis was carried out to map technologies onto the CFRP recycling supply chain.

Abstract: According to the unique advantage of the ultrasonic vibration processing in brittle materials, a new processing method, combining ultrasonic vibration and high-speed milling, was presented in this paper, to investigate an adaptation of high-quality and efficient processing in carbon fiber composites. Based on vibration theory, the special ultrasonic vibration milling device suitable for high speed machining centers was designed. Taking into account of a range of issues existing in contact electrical transport under high-speed processing, the contactless induction power transmission system was developed, and the impacts of load, frequency, air gap size as well as the existence of compensation on the transmission performance was discussed. The study shows that carbon fiber composites processed under ultrasonic vibration with high speed, high quality and high efficiency are adapted. Keywords: ultrasonic vibration milling; carbon fiber composites; contactless induction; tool wear

Abstract: In order to overcome the limitations of conventional ultrasonic testing method to detect small defects of carbon fiber composite material, ultrasonic nonlinear detection method was proposed based on finite amplitude. Firstly the detection mechanism of finite amplitude method was studied, then the detection model was created, and ultrasonic nonlinear characteristics of carbon fiber composites was analyzed by finite element simulation, finally relative non-linear coefficients follow the change of defect length and width show that the finite amplitude method has a high sensitivity to detect small defects.

Abstract: Currently, Carbon Fiber Reinforced Non-Metal Composites (CFRC) are commonly applied in structural components of aircrafts. Frequently, these elements need to be drilled for their assembly in the final product. Chips close to powder are formed when this kind of material is machined. Because of this, drilling processes are mostly performed in absence of cutting fluids. High quality requirements are demanded for holes due to the fact than those elements are placed in key components of the aircrafts. The most relevant defects that can be produced in the dry drilling of CFRC are located in the both tool input and tool output. These defects are known as Break-IN (B-IN) and Break-OUT (B-OUT). This paper reports on the results of a comparative study of different methodologies for evaluating those defects. First of them is based on the analysis of the diameter deviation. Second procedure is based on the damaged area. Both parameters have been measured making use of image analysis techniques. Obtained results have revealed that damaged area based method is more sensitive to hole changes.

Abstract: The demand for mechanical fastening in composite materials is increasing due to their potential in large assemblies, aerospace and automotive industries. In practice, small components are integrated into large assemblies drilling holes in composite materials. Drilling defect free holes in composite presents many challenges during part assembly and services. This study presents the effects of cutting parameters used for drilling holes in glass fiber reinforced polymeric (GFRP) composites and hybrid fiber reinforced polymeric (HFRP) composites. Both the composites plates of 3 mm thickness were fabricated using a hand lay-up technique for the purpose of evaluating the effects of parameters on the quality of drilled holes. The holes were drilled using a 5 mm solid carbide twist drill at different spindle speed and feed rate. The quality of holes was assessed with respect to damage factor (F_d) and surface roughness (Ra) of the drilled holes. Results showed that the HFRP composite experienced lower damage factor (F_d) as compared to GFRP composite at lower feed rate or spindle speed. Scanning electron microscopic (SEM) examination revealed that the occurrence of delamination, fiber pull-out and matrix cracking was accelerated in the drilled holes at high spindle speed and feed rate.

Abstract: In this work, a method to eliminate ice on wind turbine blade by using carbon fiber composites was put forward. To prove that this idea is feasible, a carbon fiber composite panel with its ends soaked by the conductive silver paste was fabricated and surface temperature of it at three levels of voltages was measured. The surface temperature of the composite panel increased significantly and finally retained a constant, which shows that the carbon fiber composites can be used to eliminate ice when the glass fabric composite blades are covered by the carbon fiber composites.

Abstract: Owing to the excellent properties, carbon fiber composites have been applied in many fields. This article outlined the new applications and development trends of carbon-fiber composite materials, and pointed out some problems existing in their development. Moreover, a new kind of billiard cloth made of the mixture of carbon fiber composites and wool was argued in the paper.

Abstract: Transient temperature-fields of carbon fiber composites which contained defects were numerically simulated. When the total heat was constant, the influences of different pulse heating methods on thermal imaging temperature difference and contrast of carbon fiber composites surface were analyzed. The peak values of temperature difference and contrast declined progressively with the progressive decrease of heat flux, and all the peak values postponed. With the increase of initial heat and the decrease of second heat, the peak values of temperature difference and contrast increased progressively at the first emergence, and declined progressively at the second emergence. With the progressive increase of interval, the extreme values of temperature difference and contrast were almost invariant at the first emergence, and declined by degree at the second emergence.

Abstract: Large structural composite sandwich panels (approx. 2x4 m2) were found to have cracks in the honeycomb core. The core was made out of a number of Nomex honeycomb blocks having different densities. These were first machined and adhesively bonded into the final shape. The CFRP skins were then added and the sandwich panel was cured in an autoclave applying elevated temperature and pressure. Acoustic emission monitoring was done during 17 hours of processing in the autoclave using a six channel AE system. AE events from cracking of the honeycomb core were registered and could be identified in time and space. The results from AE monitoring were very useful for modifying the process parameters and overcome the cracking of the core.