IHI Infrastructure Systems Co Ltd

Ōsaka, Japan

IHI Infrastructure Systems Co Ltd

Ōsaka, Japan

Time filter

Source Type

Patent
Ihi Infrastructure Systems Co. and IHI Corporation | Date: 2015-02-09

An interface inspection method according to the present invention includes a step S1 of transmitting ultrasound to a composite structure to be inspected, via an ultrasound generating unit adapted to generate ultrasound of a frequency suitable for a member making up the composite structure and acquiring a signal waveform by receiving a reflected wave from the composite structure using a receiving unit; a step S2 of performing signal processing on the acquired signal waveform and acquiring signal amplitude versus frequency characteristics; and a step S3 of determining an interface condition of the composite structure based on an amplitude in a frequency band unique to the composite structure as observed on the signal waveform subjected to signal processing.


Patent
IHI Infrastructure Systems CO. and IHI Corporation | Date: 2013-04-03

A welding method wherein the root gap aperture displacement is measured before welding begins, and a welding material having a Mn/S ratio and a Mn/Si ratio compatible with the measured root gap aperture displacement is selected from gas-shielded arc welding materials. Gas-shielded arc welding is then performed using the selected welding material.


Patent
IHI Infrastructure Systems Co. and IHI Corporation | Date: 2013-07-31

A method for measuring the degree of fusion involves: a step for creating a dividing pulse amplitude curve by using a probe that emits ultrasound beams; a step for scanning the probe that emits ultrasound beams at a predetermined angle on a surface that has weld beads of multiple welding specimens having different degrees of fusion and for obtaining beam path length information from the dividing pulse amplitude curve and the height of an F echo that returned to the probe after hitting the fused section of a welding site; and a step for obtaining a regression formula expressing the relationship between the beam path length information and the degree of fusion.


Patent
IHI Infrastructure Systems Co. and IHI Corporation | Date: 2015-02-11

A root opening width variation before start of welding is measured, and a welding consumable having Mn/S and Mn/Si ratios accommodating the measured root opening width variation is selected from among gas shielded arc welding consumables.


Patent
Ihi Infrastructure Systems Co. and IHI Corporation | Date: 2015-06-10

A method for measuring the height of lack of penetration includes steps of: using a probe applying an ultrasonic beam to an object to define a dividing curve of an echo height; using the probe applying the ultrasonic beam to the object at a predetermined angle to scan surfaces of a plurality of weld test samples having different heights of lack of penetration, a weld bead being disposed on the surface; obtaining beam path length information based on the dividing curve of the echo height and the height of an F echo reflected by a part of lack of penetration of a weld and returned to the probe; and formulating a regression equation showing a relation between the beam path length information and the height of lack of penetration.


Patent
IHI Corporation and Ihi Infrastructure Systems Co. | Date: 2015-07-01

An interface inspection method according to the present invention includes a step S1 of transmitting ultrasound to a composite structure to be inspected, via an ultrasound generating unit adapted to generate ultrasound of a frequency suitable for a member making up the composite structure and acquiring a signal waveform by receiving a reflected wave from the composite structure using a receiving unit; a step S2 of performing signal processing on the acquired signal waveform and acquiring signal amplitude versus frequency characteristics; and a step S3 of determining an interface condition of the composite structure based on an amplitude in a frequency band unique to the composite structure as observed on the signal waveform subjected to signal processing.


Yoshitake I.,Yamaguchi University | Tsuda H.,IHI Infrastructure Systems Co. | Itose J.,Yamaguchi University | Hisabe N.,Mitsubishi Group
Construction and Building Materials | Year: 2014

High modulus carbon fiber reinforced polymer (CFRP) laminates are often used to strengthen steel plate girder bridges. In the case of environmental load, discrepancy in the coefficients of thermal expansion (CTE) between the steel and CFRP can generate interfacial stresses along the CFRP-bond line. Thermally-induced stresses may accelerate premature debonding of the CFRP, thereby decreasing the efficacy of CFRP-strengthening. The present study examines thermal deformation and the strength of CFRP-steel composite elements exposed to cold temperature. The experimental program investigates long-term deformation of a composite strip subjected to a sustained flexural load and structural performance of an H-beam strengthened with CFRP laminate under cyclic cold temperature variation. The experimental observations verify that the CFRP laminates are firmly bonded to the steel substrates (steel-strip and H-beam) even in the cold temperatures. It should be emphasized that premature debonding of the CFRP laminates was not observed in these severe environmental conditions. In addition, the flexural test confirms that thermal deformation due to the discrepancy is negligible in cold temperature of mild weather condition. © 2014 Elsevier Ltd. All rights reserved.


Tokuchi T.,IHI Infrastructure Systems Co Ltd | Kaifuku S.,IHI Infrastructure Systems Co Ltd
Sustainable Bridge Structures - 8th New York City Bridge Conference, 2015 | Year: 2015

Binh bridge, located in Haiphong city, Vietnam, a 3-span cable-stayed bridge with composite girders and a center span of 260 m, was opened to traffic in 2005 (Construction Report for “Binh bridge” in Vietnam). In 2010, 3 ships swept upstream by a typhoon collided with the bridge, resulting in serious damage to the edge girder and several cables. Repair and rehabilitation works on the bridge were awarded to IHI Infrastructure Asia Co., Ltd. The complexity of repairing a composite girder cable-stayed bridge required the utilization of innovative methods in the analysis, planning and execution of the repair works. The repair works included, cutting of the damaged steel girders and on-site welding of new plates and stay cable replacement utilizing the adjacent stay cables in temporary hanger system that reduced erection loads during repair works. © 2015 Taylor & Francis Group, London.


Inoue M.,IHI Infrastructure Systems Co.
Bridge Structures | Year: 2012

For a suspension bridge, the balance of design, fabrication, and erection of the hangers presents a major concern. The hangers play an important role for the bridge geometry and are very sensitive to length error. This paper focuses on the characteristics of suspension bridge hangers through a study of numerical analyses. Difference between bridges with one hanger rope at a hanger location per each cable plane and with two or more hanger ropes in the longitudinal direction are studied in detail. Erroneous fabrication of angers may cause undesirable results for a real bridge because two or more hangers in the longitudinal direction at one hanger location are occasionally modeled as one hanger element in the design. This simplification may not represent the actual behavior of hangers on suspension bridges. The findings of this study provide important clues to the fabrication requirements of hangers for suspension bridges. © 2012 - IOS Press and the authors. All rights reserved.


Patent
IHI Infrastructure Systems Co. | Date: 2013-04-12

A plurality of movable temporary hangers 7 are placed on a stay cable 4B hung in tension above a target stay cable 4C, and then the target stay cable 4C is held on a lower portion of the temporary hangers 7. Then, the target stay cable 4C held with the temporary hanger 7 is detached from a bridge deck 3 and a main tower 2. Then, the target stay cable 4C and the temporary hangers 7 holding the target stay cable 4C are moved toward the bridge deck 3 and removed.

Loading IHI Infrastructure Systems Co Ltd collaborators
Loading IHI Infrastructure Systems Co Ltd collaborators