Sumitomo Electric Industries, Limited

Kyoto University

Tokyo Rope Mfg. Co., Ltd.

Tokyo Rope Manufacturing Co., Ltd.

Sumitomo (sei) Steel Wire Corp.

Masashi Oikawa

Masato Yamada

Yoshiyuki Matsubara

Kazuhiko Tsukada

Shinji Nakaue

Toru Yamamoto

Toshiyuki Moriya

Kazuyoshi Chikiri

Hiroaki Itoi

Ippei Furukawa

Sadanori Shiiki

Shuichi Tanaka

Kiminori Matsushita

Naoki Sogabe

Toshiro Kido

Toshiyuki Kobayashi

Kazumasa Okubo

Michio Imai

Shinichi Yamanobe

A tension measuring method installs a reel having a cylindrical coil forming part on a cable to be measured, forms a coil by winding a conductor around the coil forming part, measures a magnetic hysteresis loop of the cable by supplying a current to the coil to generate a magnetic field, and computes a tension of the cable using a parameter determined from the hysteresis loop. A magnetic field sensor and a magnetic flux sensor are provided inside a through hole in the coil forming part, and the cable is positioned inside the through hole. The magnetic field is varied so that the hysteresis loop includes a near-saturation magnetization region, to measure the hysteresis loop using the sensors. The parameter is selected from a magnetic flux or a magnetic flux density, a remanent magnetization, a coercivity, a magnetic permeability, and a hysteresis loss in the near-saturation magnetization region.

Tension measuring method

A coated PC steel stranded cable includes: a stranded cable in which a plurality of elemental wires each composed of steel are twisted together; an anti-corrosive coating having an outer circumferential portion that coats an outer circumference of the stranded cable; an outer coating that coats an outer circumference of the anti-corrosive coating; and an optical fiber provided at a position inwardly of an outer circumferential surface of the outer coating and corresponding to a strand groove in the stranded cable so as to follow expansion and contraction of the stranded cable.

Coated PC steel stranded cable

To provide a concrete-reinforcing shaped body containing concrete-reinforcing fibers and having a plate-like shape. The concrete-reinforcing fibers each preferably have a diameter of 0.3 mm or smaller and a length of 5 mm or larger and 25 mm or smaller.

Concrete-reinforcing shaped body, method of manufacturing the same, structure of packaging concrete-reinforcing shaped body, and method of mixing fiber-reinforced concrete

A tension measurement apparatus that can carry out tension measurement of superior reproducibility with high sensitivity even for a target object of a stranded wire structure is provided. A cylindrical magnetizer arranged to surround a portion of a long magnetic element that becomes the target object of measurement direct-current magnetizes the magnetic element in the longitudinal direction up to the range of approach to saturation magnetization. Using a Hall element (magnetic sensor) arranged in proximity to the magnetic element at the central region in the longitudinal direction of the magnetic domain, the spatial magnetic field intensity in the neighborhood of the surface of the magnetic element, greatly differing corresponding to stress variation, is detected. Based on the detection value, the tension acting on the magnetic element is measured. Accordingly, a measurement result of superior reproducibility with high sensitivity is obtained. The tension measurement apparatus is applicable even to a target object of a stranded wire structure.

Tension measurement apparatus

Growing community of inventors

Itami, Japan

Masashi Oikawa