Papers by Keyword: CFRTP

Abstract: In this study, electrochemical measurements and observations investigated galvanic corrosion behavior between various metals with or without projection-shaped Ni–Cu alloy plating film and carbon-fiber-reinforced thermoplastic (CFRTP) of corroded areas. Stainless steel, aluminum alloy, and CFRTP plates were prepared. Ni and Ni–Cu alloy electroplating were performed on the stainless steel plate. Electroless zinc plating, Ni, and Ni–Cu alloy electroplating were performed on the aluminum alloy plate. The galvanic current between the metal and CFRTP plates was measured using an electrochemical measurement system. The test solution was 0.06 mol/L NaCl aqueous solution. For Stainless steel/CFRTP, the galvanic current flow was negligible with and without the Ni–Cu alloy plating film. For aluminum alloy/CFRTP without the Ni–Cu alloy plating film, the galvanic current ranged from-80 to-120 μA/cm² at a test temperature of 60°C. For aluminum alloy with the Ni–Cu alloy plating film, the galvanic current ranged from-60 to-80 μA/cm². The galvanic current for the aluminum alloy plate with Ni–Cu alloy plating was lower than that of the aluminum alloy plate without Ni–Cu alloy plating film. The result suggests that the formation of the Ni–Cu alloy plating on the aluminum alloy improves corrosion resistance.

Abstract: Model-based quality control has the potential to reduce the reject rate in the production of fiber-reinforced plastics (FRP) components. After all the cross-market establishment of FRP, undesirable quality deviations often occur with new materials or component shapes. The quality control uses the component quality (e.g. component angle, crystallinity, fiber orientation, pore content) as the control variable. As a key component of the control, a process model is developed to link the process parameters (press pressure, press duration and tool temperature) with the quality parameters. Knowledge of the process-determining cause-effect relationships is necessary to ensure that different quality parameters are in the target value at the same time. Based on experimental tests, these interrelationships are determined using methods of statistical test planning and serve as the basis for model-based quality control. As a result, it has been shown that the targeted control of the component angle is possible in a range of about ±1° by using the control parameters, tool temperature and pressure, which have a significant influence on the quality. In the next step, further quality characteristics are included in the control system in order to demonstrate the ability to control the quality of complex component specifications. Model-based quality control is particularly promising for the reduction of the process run-in phase and thus for the reduction of the reject rate.

Abstract: The purpose of this study is to reveal the effects of the modification of the sheet of Polypropylene (PP) with fine glass fibers for repair of the Carbon Fiber Reinforced Thermo Plastics (CFRTP) on the recover ratio of degraded mechanical properties of damaged CFRTP after impact bending. Impact damaged specimen was repaired by inserting tiny melted sheet of PP modified with fine glass fibers to be assimilated with PP matrix around the surface of damaged area. Model specimens having cut reinforcements were prepared for compressive buckling tests to investigate the effect of the modification on mechanical behaviors under compressive stress due to the impact bending. The recovering ratio defined as the ratio of compressive buckling strength of damaged model specimen to that of un-damaged specimen was investigated. The recovering ratio of model specimen after the repair was about 49% when the unmodified PP sheet was used to repair. On the other hand, when the weight content rate of fine glass fibers was 2.0wt%, about 73% of recovering ratio was successfully obtained. The appropriate condition of the weight content rate was shown for repairing the damaged part of the CFRTP used in this study.

Abstract: To use Carbon Fiber Reinforced Thermoplastics (CFRTP) for automobile applications, mechanical properties of CFRTP under actual operating temperatures are needed to be clarified. When focusing on heat resistance of CFRTP, to use Polyphenylenesulfide (PPS) for the matrix is desirable. However, the effect of high temperature on mechanical properties of CFRTP using PPS has not been clarified yet. In this study, single fiber pull-out tests of CF/PPS model composites under high temperature were conducted to reveal the fiber/matrix interfacial properties.

Abstract: Significant stiffness reduction of the plate spring due to delaminations around the interwoven cloths could be prevented by using CFRTP (carbon fiber cloth and Polyethylene Terephthalate (PET)) rather than that by using CFRP (carbon fiber cloth and epoxy), when ultra high cyclic loading was applied to the plate spring under high humidity condition. To explain the result, the prediction model of stiffness reduction was introduced considering time-dependent crack propagation accompanying with creep deformation around the crack tip. Stiffness reduction of CFRP under high humidity condition was not only determined by cyclic crack propagation but also by time-dependent crack propagation accompanying with creep deformation around the crack tip. It was found that CFRTP was effective material of the plate springs on vibration conveyer for the uses under high humidity condition to prevent significant stiffness reduction, where the crack propagation accompanying with creep deformation should be prevented around the crack tip.

Abstract: This paper investigated the stiffness reduction of the plate spring made of CFRP (Carbon cloth and epoxy) subjected to ultra high cyclic fatigue loading under high relative humidity. For practical uses, this paper proposes a new design which prevents the significant degradation with stiffness change of the plate spring at high humidity. Remarkable stiffness reduction of the plate spring due to cracks and delaminations around inter layer could be prevented by using CFRTP rather than that by using CFRP, when ultra high cyclic loading was applied to the plate spring under high humidity condition.