Abstract: A method is disclosed for testing bonded part integrity of bonded structures with increased sensitivity and in a nondestructive manner. The method includes the steps of: mixing a piezoelectric material or an electrically conductive material with an adhesive agent, curing the adhesive agent in between bonding target objects, electrically connecting the bonding target objects to one another, causing an electric current to flow through the bonding target objects to measure a quantity of electric charges flowing between the bonding target objects, and determining existence of bonding damage between the bonding target objects and the adhesive agent based on the quantity of electric charges and predicting a remaining life span of the bonded structures based on a data indicating a correlation between the quantity of electric charges and a predetermined fatigue life.

Abstract: A fuel cell stack assembly includes a wire for assembling a fuel cell stack, which can maintain a constant surface pressure on the fuel cell by utilizing a wide elasticity range of the wire and ensure a high fastening force even with a small amount of material, thus making the fuel cell lightweight and maximizing the package efficiency. For this purpose, the present invention provides a fuel cell stack assembly including: at least one wire for fastening end plates mounted on both end portions of a fuel cell stack; at least one tensioner mounted on at least one portion of the top surface of an upper end plate; at least one tension guide each of which includes a central guide for guiding up and down movement of the tensioner and surrounds the tensioner; at least one upper guide mounted on both sides of the top surface of the upper end plate for guiding the wire; and at least one lower guide mounted on both sides of the bottom surface of a lower end plate for guiding the wire.

Abstract: A bearing assembly includes a spherical journal and a hemispherical bearing that is made of a fiber reinforced composite and has a bearing surface for establishing a spherical pair with the spherical journal. The fiber reinforced composite can be constructed by arranging a uni-directional prepreg, woven fiber prepregs and staple-fiber prepregs in a variety of configurations, and thermoplastic resin particles or self-lubrication particles are uniformly provided on the bearing surface. It is possible to alleviate stress concentration generated on the bearing surface by forming a plurality of air channels capable of imparting directivity on an outer surface of the hemispherical bearing.

Abstract: A spherical bearing assembly manufacturing apparatus and its manufacturing method is disclosed. The spherical bearing that houses and supports a spherical journal is manufactured with fiber reinforced composite as a material. The spherical bearing assembly manufacturing apparatus consists of a mold, plunger, and first and second grippers. The mold has a cavity for molding fiber reinforced composite into a spherical bearing, and a first press surface for supporting fiber reinforced composite, and a first guide hole communicated with the cavity. The plunger has a second press surface for molding the fiber reinforced composite housed in the cavity into a spherical bearing, and a second guide hole formed in the center of the second press surface. In the first gripper is formed a hole in which the edge on one end of the spherical journal is housed. In the second gripper is formed a recessed portion in which the edge on the other end of the spherical journal is housed.

Abstract: A spherical bearing assembly manufacturing apparatus and its manufacturing method is disclosed. The spherical bearing that houses and supports a spherical journal is manufactured with fiber reinforced composite as a material. The spherical bearing assembly manufacturing apparatus consists of a mold, plunger, and first and second grippers. The mold has a cavity for molding fiber reinforced composite into a spherical bearing, and a first press surface for supporting fiber reinforced composite, and a first guide hole communicated with the cavity. The plunger has a second press surface for molding the fiber reinforced composite housed in the cavity into a spherical bearing, and a second guide hole formed in the center of the second press surface. In the first gripper is formed a hole in which the edge on one end of the spherical journal is housed. In the second gripper is formed a recessed portion in which the edge on the other end of the spherical journal is housed.

Abstract: A structure and method for bonding heat-insulating protection walls of a liquefied natural gas carrier is provided. Each of the heat-insulating protection walls is formed of an insulation foam layer and a fiber-reinforced composite reinforcing sheet attached to a surface of the insulation foam layer. The heat-insulating protection walls are provided in a tank of the liquefied natural gas carrier in a mutually adjoining relationship and bonded to one another at a junction to keep the tank cold. The structure includes a fiber-reinforced composite joint sheet positioned in alignment with the juncture of the heat-insulating protection walls and bonded to the fiber-reinforced composite reinforcing sheet by an adhesive agent and a spacer means interposed between the fiber-reinforced composite reinforcing sheet and the fiber-reinforced composite joint sheet for keeping the adhesive agent uniform in thickness.

Abstract: A probe card is used in conducting a visual test for a target test object through simultaneous contact of the probe card with each and every electrode pad of the target test object. The probe card includes a plurality of probes composed of conductive wire strands and having elastically deformable contact parts so curved as to make contact with electrode pads of a target test object. The contact parts are oriented in one and the same direction and extend in a parallel relationship with one another. The probe card further includes a first insulating block for fixedly securing one end parts of the probes, a second insulating block for fixedly securing the other end parts of the probes and a mounting plate for holding the first and second insulating blocks in such a manner that the contact parts of the probes protrude outwardly.

Abstract: A probe card is used in conducting a visual test for a target test object through simultaneous contact of the probe card with each and every electrode pad of the target test object. The probe card includes a plurality of probes composed of conductive wire strands and having elastically deformable contact parts so curved as to make contact with electrode pads of a target test object. The contact parts are oriented in one and the same direction and extend in a parallel relationship with one another. The probe card further includes a first insulating block for fixedly securing one end parts of the probes, a second insulating block for fixedly securing the other end parts of the probes and a mounting plate for holding the first and second insulating blocks in such a manner that the contact parts of the probes protrude outwardly.

Abstract: A method is disclosed for testing bonded part integrity of bonded structures with increased sensitivity and in a nondestructive manner. The method includes the steps of: mixing a piezoelectric material or an electrically conductive material with an adhesive agent, curing the adhesive agent in between bonding target objects, electrically connecting the bonding target objects to one another, causing an electric current to flow through the bonding target objects to measure a quantity of electric charges flowing between the bonding target objects, and determining existence of bonding damage between the bonding target objects and the adhesive agent based on the quantity of electric charges and predicting a remaining life span of the bonded structures based on a data indicating a correlation between the quantity of electric charges and a predetermined fatigue life.

Abstract: A probe card is used in conducting a visual test for a target test object through simultaneous contact of the probe card with each and every electrode pad of the target test object. The probe card includes a plurality of probes composed of conductive wire strands and having elastically deformable contact parts so curved as to make contact with electrode pads of a target test object. The contact parts are oriented in one and the same direction and extend in a parallel relationship with one another. The probe card further includes a first insulating block for fixedly securing one end parts of the probes, a second insulating block for fixedly securing the other end parts of the probes and a mounting plate for holding the first and second insulating blocks in such a manner that the contact parts of the probes protrude outwardly.

Abstract: The present invention discloses a bearing assembly capable of assuring mechanical strength and reducing a friction coefficient and stress concentration, and a method for manufacturing the same. The present invention comprises a spherical journal and a hemispherical bearing that is made of a fiber reinforced composite and has a bearing surface for establishing a spherical pair with the spherical journal. The fiber reinforced composite can be constructed by arranging a uni-directional prepreg, woven fiber prepregs and staple-fiber prepregs in a variety of configurations, and thermoplastic resin particles or self-lubrication particles are uniformly provided on the bearing surface. It is possible to alleviate stress concentration generated on the bearing surface by forming a plurality of air channels capable of imparting directivity on an outer surface of the hemispherical bearing.

Abstract: A probe card is used in conducting a visual test for a target test object through simultaneous contact of the probe card with each and every electrode pad of the target test object. The probe card comprises a plurality of probes composed of conductive wire strands and having elastically deformable contact parts so curved as to make contact with electrode pads of a target test object. The contact parts are oriented in one and the same direction and extend in a parallel relationship with one another. The probe card further comprises a first insulating block for fixedly securing one end parts of the probes, a second insulating block for fixedly securing the other end parts of the probes and a mounting plate for holding the first and second insulating blocks in such a manner that the contact parts of the probes protrude outwardly.

Abstract: The present invention is to provide a machining tool bar in which mechanical machining properties are improved by using high stiffness composite material. According to the present invention, the tool bar includes an adaptor constructed to be coupled to a driving device, a body constructed to be mounted with cutting tools and a tip constructed to be supported by a workpiece, said body is constructed to be mounted with one or more cutting tools, wherein the adaptor and tip are made of metal material, the body is made of composite material having high stiffness, the composite material constructing the body is formed to surround at least a portion of the adaptor and at least a portion of the tip, and the metal material constructing the adaptor and tip and the composite material constructing the body are securely joined to each other in an interface therebetween.

Abstract: The propeller shaft comprises a transmission shaft 10 consisting of a hollow metal tube 11 with excellent torque transmissibility and a composite material prepregs 12 having higher specific stiffness than a metal material and stacked to the inner surface of the metal tube, and metal yokes 40 mounted on both ends of the transmission shaft and assembled with other devices. The composite material prepregs is co-cure bonded while applying an axial compressive preload to the transmission shaft and creating a vacuum in a space between a vacuum bag inserted in the transmission shaft and the composite material prepregs of the transmission shaft. Teeth 43 or embossments 44, and adhesive-retaining grooves 45 are formed on inner surfaces of the metal yokes, so the transmission shaft is desirably compression-fitted into the metal yokes. Accordingly, the propeller shaft has advantages of securing improved impact, abrasion, and water resistance.

Abstract: The present invention is to provide a machining tool bar in which mechanical machining properties are improved by using high stiffness composite material.

Abstract: The present invention relates to a method for repairing and reinforcing an underground pipe. The method of the present invention comprises the steps of inserting an inner mold made of flexible material through the interior of a reinforcing element including a fiber preform surrounded by impermeable inner and outer tubes made of the flexible material and combining the inner mold with the reinforcing element; positioning a combined element, which includes the reinforcing element and the inner mold, into the underground pipe to be repaired and reinforced; injecting and expanding the inner mold with and by high temperature fluid, and brining the reinforcing element into close contact with an inner wall of the underground pipe; injecting the reinforcing element with thermosetting resin; and removing the inner mold after the thermosetting resin has been cured.

Abstract: The propeller shaft comprises a transmission shaft 10 consisting of a hollow metal tube 11 with excellent torque transmissibility and a composite material prepregs 12 having higher specific stiffness than a metal material and stacked to the inner surface of the metal tube, and metal yokes 40 mounted on both ends of the transmission shaft and assembled with other devices. The composite material prepregs is co-cure bonded while applying an axial compressive preload to the transmission shaft and creating a vacuum in a space between a vacuum bag inserted in the transmission shaft and the composite material prepregs of the transmission shaft. Teeth 43 or embossments 44, and adhesive-retaining grooves 45 are formed on inner surfaces of the metal yokes, so the transmission shaft is desirably compression-fitted into the metal yokes. Accordingly, the propeller shaft has advantages of securing improved impact, abrasion, and water resistance.

Abstract: Disclosed herein is, a composite squirrel cage rotor having a polymer resin part containing powder of high magnetic permeability and method for fabricating it. The composite squirrel cage rotor includes a rotating shaft, an inner core, a polymer resin part that fills the cavity of the squirrel cage conductor and contains powder of high magnetic permeability. A squirrel cage conductor is positioned outer to portion of the polymer resin part, is formed of, material having high electric conductivity, and provided with a plurality of axial slots.

Abstract: Disclosed herein is a coreless AC Induction motor. The motor comprises a cup type coreless rotor. A rotating shaft is combined with the cup type coreless rotor. An induction rod is inserted into the cup type coreless rotor to guide a magnetic flux from the stator effectively. A stator is positioned around the coreless rotor. The cup type coreless rotor comprises a squirrel cage-shaped conduction cylinder and composite material or polymer resin. The squirrel cage-shaped conduction cylinder is made of material having high electric conductivity, such as aluminum or copper, and has plurality of slots along the axis of the squirrel cage-shaped conduction cylinder. The composite material or polymer resin fills the slots of the squirrel cage-shaped conduction cylinder to make up for the low stiffness of the squirrel cage-shaped conduction cylinder.

Abstract: A method of repairing or reinforcing worn-out underground buried drainpipes by a resin transfer molding process using both flexible tubes and bagging films is disclosed. In the method of this invention, a reinforcement is primarily inserted into a desired position within a target worn-out drainpipe buried underground. The reinforcement consists of a fiber preform internally having a flexible tube, such as a silicon tube, axially extending along the central axis of the preform and wrapped with an adhesive-coated flexible film as a bagging film to provide protection from sewage or underground water. The flexible tube is, thereafter, expanded to bring the fiber preform into close contact with the interior surface of the target drainpipe. The opposite ends of the reinforcement are sealed with two lids. Thereafter, thermosetting resin is transferred into the fiber preform, thus allowing the fiber preform to be impregnated with the thermosetting resin.