Juyeop Park

MWCNTs (multiwalled carbon nanotubes) were applied to fiber-reinforced composite materials with phenolic resin having flame retardance for the composite heating panels of railroad vehicles. Instead of dispersing MWCNTs in the matrix, the surface of a pristine plain-weave glass fiber fabric was coated with MWCNTs through a series of dip-coating and drying processes, followed by the resin infusion of the phenolic resin to make the composite heating panel. Before and after the resin infusion process, low percolation thresholds of 0.00216 wt%_MWCNT (weight percent of MWCNTs) and 0.001 wt%_MWCNT, respectively, were achieved, as were very high electrical conductivities of 47.5 S/m at 0.210 wt%_MWCNT and 26.7 S/m at 0.116 wt%, respectively. The low threshold and high conductivity can be attributed to the formation of electrical pathways directly onto the glass fabrics. It was confirmed that mechanical properties such as modulus, strength, and maximum strain were at the same level as those of the pristine glass fabric composite. The heating performance with temperature uniformity, as well as the electrical and mechanical properties, indicates that the resin-infused glass fabric composite having MWCNTs directly coated onto the fabric surface can be a solution for lightweight structural composite heating panels for railway vehicles.

The thermal expansion of rails during summer causes buckling, which is a primary cause of major accidents such as train derailments. Although operating organizations have been making various efforts to solve this problem, the effect is insignificant. Therefore, thermal insulation paint has been recently applied to rail tracks to confirm its excellent temperature reduction effect and sustainable durability. However, the painting method is time-consuming for on-site construction and uniform work quality is difficult to maintain because it is greatly affected by the outdoor environment. Therefore, in this study, we developed a fabric-type thermal insulation paint that can be prefabricated with uniform quality and easily installed and dismantled on-site. In particular, fabrics suitable for applying thermal insulation paints were selected, and the effect of the coating thickness on the thermal insulation performance was evaluated. In the future, the application of fabric-type thermal insulation paint is expected to contribute to the efficient temperature reduction of rails in summer and improve driving safety.

Because railroads are specialized means of mass transportation, safety is extremely important because accidents can lead to major disasters. However, every summer, owing to the deformation of the rail caused by the increase in the temperature of the rail, safety problems occur, and there is no fundamental solution to this problem. To address this situation, research has been conducted in which a thermal insulation paint is applied to the continuous welded rail (CWR), and excellent effectiveness has been demonstrated. However, long-term performance impact analysis of vibrations caused by train operation in actual field applications is insufficient. Therefore, in this study, the effect of the change in thermal insulation performance caused by rail vibration was evaluated. A vibration test was conducted by simulating the vibration environment of the railway site, and the changes in thermal insulation performance and uniformity were observed at specific intervals. The thermal insulation paint showed excellent vibration durability by maintaining the level of performance and uniformity, even after prolonged exposure to vibration.