Ihi Corporation

Toppan Printing Co., Ltd.

Ihi Infrastructure Systems Co., Ltd.

Junko Yamada

Naoyuki Matsumoto

Daiki Okita

Toru Murakami

Koutarou Inose

Satoshi Gocho

Akira Katou

Yoshihiko Nakamura

Shigenari Yasui

Shota Nakanishi

Shinya Osawa

Irradiation with a laser beam is performed along a welding bead, while the laser beam is aimed, as an irradiation point of the laser beam, at a contact point between a deck plate and a U-rib that is contained in a non-welded portion of a root part, from a side of the welding bead of the root part. Thereby, it is possible to remove a crack beginning at the non-welded portion of the root part generated at a joining portion between the deck plate and the U-rib of a steel floor slab, by the irradiation with the laser beam.

Repairing laser welding method and repairing laser welding device

Provided is a crack repair method of melting and eliminating a crack generated in a steel material, the method including holding a tab plate in surface contact with the steel material in which the crack is generated, thereafter continuously irradiating the tab plate to a first end portion of the crack in the steel material with a laser beam, and subsequently continuously irradiating the crack with the laser beam along the crack to a second end portion of the crack to melt and eliminate the crack. Consequently, when eliminating the crack generated in a constituent member of an existing structure or a constituent member such as a machine component, the crack can be eliminated without forming a through hole in the constituent member.

Crack repair method

Paper which exhibits more favorable forgery prevention effect is provided. Paper contains first and second surface regions opposed to each other and an intermediate region interposed between the first and second surface regions. Each of the first and second surface regions and the intermediate region contains cellulose fibers. At least the first surface region further comprises functional fibers which, upon reception of a physical stimulus, make a response different from that made by the cellulose fibers to the physical stimulus. The functional fibers contained in the first surface region are mingled with the cellulose fibers in the first surface region and are oriented in one direction which is parallel or oblique to one main surface of the paper.

Paper, process for producing the same, and printed article

Growing community of inventors

Tokyo, Japan

Junko Yamada