Abstract: A bearing steel has improved insulation performance by forming a continuous insulating film. The bearing steel includes 0.65 to 1.0 mass % of carbon (C), 1.6 to 2.0 mass % of chromium (Cr), 1.5 to 3.0 mass % of aluminum (Al), 0.8 to 1.2 mass % of manganese (Mn), 0.7 to 1.0 mass % of silicon (Si), 0.1 to 0.3 mass % of nickel (Ni), 0.08 to 0.12 mass % of molybdenum (Mo), and a balance of iron (Fe), in which an oxynitride layer including a nitride layer and an oxide layer is formed on the surface of a material.

Abstract: A method of manufacturing a composite material through a wet compression molding (WCM) process is disclosed. The internal pressure of a mold is controlled so that productivity may be improved due to process automation through application of a resin using a robot. Quality of the composite material may be improved due to minimization of deformation of a foam core through control of the internal pressure of the mold.

Abstract: The present disclosure relates to an apparatus and a method for an impact test, which can easily accelerate an impact body at a desired acceleration using an air pressure and an electromagnetic force. According to an embodiment of the present disclosure, an apparatus for an impact test includes a clamping unit configured to fix a specimen, and an impact unit disposed to be spaced apart from the clamping unit and configured to accelerate and launch an impact body to collide with the specimen by an air pressure and an electromagnetic force.

Abstract: Disclosed are a composite panel having improved vibration characteristics, and a method for manufacturing the same. The composite panel includes a hybrid layer formed at a neutral axis of the composite panel, the hybrid layer including a vibration damping layer and an intermediate material layer. The composite panel also includes structural material layers laminated on both surfaces of the hybrid layer and surface layers laminated on outer surfaces of the respective structural material layers to form outermost layers of the composite panel.

Abstract: Proposed is a composite material with a helical structure and, more particularly, a composite material with a helical structure that has a vibration absorption property. The composite material includes a laminated structure formed by stacking a plurality of sheet layers on top of each other.

Abstract: A composite panel including a vibration suppression layer includes: a rubber material; a first structure material layer positioned on the vibration suppression layer and including a fiber reinforced plastic (FRP); and a second structure material layer positioned under the vibration suppression layer and including a fiber reinforced plastic.

Abstract: The present disclosure relates to an apparatus and a method for an impact test, which can easily accelerate an impact body at a desired acceleration using an air pressure and an electromagnetic force. According to an embodiment of the present disclosure, an apparatus for an impact test includes a clamping unit configured to fix a specimen, and an impact unit disposed to be spaced apart from the clamping unit and configured to accelerate and launch an impact body to collide with the specimen by an air pressure and an electromagnetic force.

Abstract: A hybrid propeller shaft may include a CFRP tube layer in which high-strength CFRP or high-elasticity CFRP, the high-strength CFRP, and the high-elasticity CFRP are laminated to form at least two layers while having different wrapping angles by a prepreg wrapping process method; and a protective layer which is formed on an outermost layer of the CFRP tube layer to protect the CFRP tube layer.

Abstract: Disclosed is a resin impregnation apparatus. The apparatus includes: a resin supply unit for supplying a resin having a predetermined viscosity downwards; a film formation unit provided at a lower side of the resin supply unit and configured to form the resin supplied from the resin supply unit into a film shape while the resin passes between a pair of rollers spaced apart from each other. The apparatus further includes a fiber supply unit for unwinding a reinforcing fiber and bringing the reinforcing fiber into contact with the film-shaped resin so that the resin is impregnated into the reinforcing fiber to form a resin-impregnated reinforcing fiber.

Abstract: A hybrid propeller shaft may include a CFRP tube layer in which high-strength CFRP or high-elasticity CFRP, the high-strength CFRP, and the high-elasticity CFRP are laminated to form at least two layers while having different wrapping angles by a prepreg wrapping process method; and a protective layer which is formed on an outermost layer of the CFRP tube layer to protect the CFRP tube layer.