Nippon Telegraph and Telephone Corporation

Masayuki Tsuda

Tadashi Minotani

Eri Matsunaga

Masahito Nakamura

Takuya Kamisho

Yosuke Takeuchi

Shota Oki

Shingo Mineta

Mamoru Mizunuma

Ryuta Ishii

Shoji Mochizuki

Takashi Sawada

Norihiro Fujimoto

Masahiro Sotoma

Jun Takeuchi

A corrosion amount estimation apparatus that estimates the corrosion amount of a metal material buried in the ground, the apparatus including: a soil adjustment unit that dries the target soil; a water permeability measurement unit that measures the water permeability of the soil after supplying water to the dried soil; and a corrosion estimation unit that estimates the corrosion amount of the metal material when buried in the soil using the water permeability.

Corrosion amount estimation apparatus and corrosion amount estimation method

An occluded hydrogen content estimation method implemented by an occluded hydrogen content estimation device performs an occluded hydrogen content estimation step in which, based on an occluded hydrogen unit content which is a content of hydrogen occluded in a metal due to a change in humidity from a wet state to a dry state, a period after the metal is placed, and meteorological data corresponding to the period for an area where the metal is located, a content of occluded hydrogen that is absorbed in the metal for the period after the metal is placed is estimated. In the occluded hydrogen content estimation step, the occluded hydrogen content is estimated by multiplying the number of rainfalls in the meteorological data by the occluded hydrogen unit content.

Storage hydrogen amount estimation method and device

A looseness detection sensor for detecting looseness of a bolt for fixing a component, including: a resonance unit arranged adjacent to a head portion of the bolt and made of an insulating material confining a high-frequency signal input externally; and a conductive member in conduction with the component across the resonance unit, wherein the conductive member is a cap put on the head portion of the bolt and includes a protrusion contacting a surface of the component.

Looseness detection sensor and method

A tire with a built-in antenna includes a radio wave transmissive resin filled in the tire and an antenna arranged in the radio wave transmissive resin, and the antenna transmits a radar wave when an antenna surface of the tire facing a radiation surface of the antenna comes into contact with a ground surface.

Tire with built-in antenna

To repair reinforced concrete easily and at low cost. An anticorrosion method includes infiltrating an anticorrosion solution held inside concrete of reinforced concrete into a vicinity of a reinforcing bar through the concrete to passivate the reinforcing bar, detecting that the anticorrosion solution is infiltrated to a surface of the concrete, and discharging, after detecting the anticorrosion solution, the anticorrosion solution to outside of the concrete to form an anticorrosive coating on a surface of the reinforcing bar.

Corrosion prevention method and corrosion prevention device

A loosening detection device according to the present embodiment includes multiple washers having holes that allow bolts to pass therethrough, and including metals insulated from each other, a transmission line that electrically connects between the metals and between the metals of the washers, and a transmission line that includes a terminal pair at one end thereof, and that has the other end electrically connected to the metals of the washer. A resonance frequency is measured from the terminal pair to detect loosening of the bolts on the basis of a change in the resonance frequency.

Looseness detection device and looseness detection method

To improve the accuracy of estimating when a fracture occurred in the metal material. In the estimation apparatus, the fracture temperature estimation unit performs estimate calculation of the fracture temperature of a fractured metal material from the hydrogen embrittlement rate of the fractured metal material, the fracture occurrence time narrowing unit performs calculation by using the temperature information of the installation environment in which the fractured metal material is installed and narrow down the period during which the fracture temperature is obtained as the fracture occurrence period of the metal material, and the fracture time estimation unit performs estimate calculation of the timing of when stress was applied to the fractured metal material during the fracture occurrence period as the timing of when a fracture occurred in the metal material.

Estimation method

An object is to support evaluation of corrosion of metal embedded in the ground such that the corrosion can be evaluated with high accuracy even if any type of soil is used. A coarseness/fineness test unit analyzes soil particles of soil that is used to evaluate corrosion of an embedded metallic material, a water supply unit supplies water to the soil, a soil stirring unit stirs the soil supplied with water, and a viscosity test unit measures fluidity of the stirred soil.

Corrosion evaluation support apparatus and corrosion evaluation support method

A bolt tightening torque management structure for a bolt for fastening a component includes: the bolt including a plurality of projections of different heights on a bearing surface of a head; a non-conductive film that is formed on the surface of the component, has a shaft hole through which a shaft of the bolt extends, and has a predetermined size; and a conductive film that has the shaft hole and a plurality of grooves, through which the projections extend, is formed on the non-conductive film, and has the same planar shape as the non-conductive film. The projections other than the projection having the smallest height are configured to be in contact with the surface of the component when the tightening torque of the bolt is appropriate. The base of each projection has a width dimensioned to close the corresponding groove.

Bolt tightening torque management structure and method

A looseness detection structure includes: a structure (transducer) T which is formed on a surface of a cable; a screw which tightens and fixes the cable in contact with the structure T; and a terminal (detection unit) which transmits a transmission signal to the structure T, receives a reception signal returning after propagating through the structure T, and detects the loosening of the screw based on a change in the reception signal.

Loosening detection structure and loosening detection method using said structure

A repair apparatus for repairing damaged reinforcing bars in a structure includes a strip-shaped conductor including conductive wires arranged in a height direction, the conductive wires being arranged in parallel, a high-frequency current generation unit configured to supply a high-frequency current between the conductive wires of a first end side of the conductor and the conductive wires of a second end side of the conductor, and a connection body configured to connect the conductive wires to each other and connect the first end side and the second end side of the conductor so that the conductive wires form a coil, and the high-frequency current generation unit supplies a high-frequency current between a conductive wire at an upper end or a lower end of the first end side of the conductor and a conductive wire at a lower end or an upper end of the second end side of the conductor.

Repair device

A sensor for detecting looseness of a plurality of bolts and nuts fixing parts includes: a non-conductive film attached to a surface of the part, which is one of the parts, including holes H from which the bolts are inserted; and a conductive film attached to the non-conductive film, configured to receive supply of a high-frequency signal, and having a same planar shape as that of the non-conductive film, wherein the planar shape is a shape in which a resonance frequency of the high-frequency signal confined in the non-conductive film is different according to a position of a loosened bolt, and the planar shape of the conductive film is a shape in which a distance between a bolt and an end portion of the conductive film is different for each of the plurality of bolts.

Looseness detection sensor and how to identify loose bolts

Reinforced concrete is protected from corrosion without conducting an operation involving exposure of rebar. A reinforced concrete structure is provided with a storage part that is formed inside concrete of the reinforced concrete structure, and that retains an anticorrosion solution. The anticorrosion solution diffuses and permeates through the concrete from the storage part, prevents the concrete in the vicinity of rebar from drying, and passivates the rebar.

Reinforced concrete structure

A loosening detection structure used to detect loosening of a bolt includes a material that is disposed between a fixing subject steel plate and a head portion of a metal bolt for fixing the steel plate and either attached to a seating surface of the head portion of the bolt or attached to a washer disposed between the steel plate and the head portion of the bolt, and that has electrical characteristics that vary in response to variation in a force for fastening the bolt to the steel plate.

Loosening detection structure, loosening detection system and method

A transducer includes a conductive sheet installed on a sheath of a cable, an insulative sheet installed on the conductive sheet, holes being formed in predetermined positions of the insulative sheet, and a conductive sheet installed on the insulative sheet, holes being formed in predetermined positions of the conductive sheet. The transducer has structure in which, when the cable is tightened by the screw from the top of the conductive sheet and fixed, the distal end of the screw comes into contact with the conductive sheet passing through the holes formed in the insulative sheet and the conductive sheet, and the conductive sheet and the conductive sheet are electrically connected.

Growing community of inventors

Musashino, Japan

Masayuki Tsuda