Shikibo Ltd.

Mitsubishi Heavy Industries Limited

Tetsuro Hirokawa

Masayasu Ishibashi

Takeshi Tanamura

Koichi Hashimoto

Hideki Sakonjo

Kentaro Shindo

Akira Fukushima

Kazunori Morimoto

Shigeru Nishiyama

Nozomu Kawasetsu

Hiroshi Sakai

Mitsuru Kondo

Akira Iriguchi

Tetsuya Ozawa

Kazuo Nakajima

A first reinforcing fiber layer is formed of reinforcing fibers which are wound around an outer periphery of a mandrel. The reinforcing fibers are aligned in parallel to a direction (+&#x3b8; direction) in which the reinforcing fibers intersect with an annular direction (0&#xb0; direction) of the mandrel, and seamlessly continue in the annular direction of the mandrel by an amount of at least one rotation.

Dry preform, annular structure made of a composite material, and manufacturing method for the annular structure

A toroidal pressure vessel having extremely high pressure resistance has laminated latitudinal reinforcing fiber layers to improve a strength in a latitudinal direction of the pressure vessel. Moreover, putting reinforcing fibers constituting those laminated latitudinal reinforcing fiber layers in continuity enables further improvement of strength in the latitudinal direction of the pressure vessel, for example compared with a case where the reinforcing fibers are divided for each layer.

Pressure vessel and method of manufacturing the same

A novel process for producing a dry preform for a composite material takes advantage of the fact that a reinforcing filament assembly, when consisting of a fiber reinforcement layer a, formed by stringing a first set of parallel strands of fiber reinforcement over a part or all of the plane within any desired shape along the straight axis, and a fiber reinforcement layer b, formed by stringing a second set of parallel strands of fiber reinforcement over the plane at an angle &#x3b8; with respect to the straight axis, such that 0&#xb0;&#x3c;&#x3b8;&#x3c;180&#xb0;, the part of the reinforcing filament assembly that consists solely of the fiber reinforcement b can be deformed as desired. According to this process, strands c of fiber reinforcement are strung using a fiber reinforcement string jig as shown in FIGS.(A) and(B). The layers of the strung strands of fiber reinforcement are brought together by a simple means such as stitching. The integrated layer is then shaped into the reinforcing filament assemblies, which are combined to form a dry preformfor making a composite material having any desired alignment of fiber reinforcement.

Method for producing dry preform for composite material

A preform for a fiber-reinforced composite material including a bent portion along a curved line for bending, a flange portion corresponding to an outer circumferential portion, and a semi-cylindrical portion formed by bending an inner circumferential portion along the curved line for bending located in a flat plane or a curved plane region. The preform is formed from a precursor having a predetermined extension. The outer circumferential portion corresponds to a first region where a first plurality of reinforced fibers is partially disposed in parallel along the curved line for bending. The inner circumferential portion corresponds to a second region constituted solely of a second plurality of reinforced fibers disposed throughout the entire area, so as to intersect the first plurality of reinforced fibers at a predetermined angle in the first region.

Preform precursor for fiber-reinforced composite material, preform for fiber-reinforced composite material, and method of manufacturing the precursor and the preform

A unidirectional three dimensional fiber structure is provided which does not require weaving, displays a high level of interlayer strength and does not suffer from cracking, and which can also be easily produced with any arbitrary cross-section. A unidirectional three dimensional fiber structure is produced by inserting a plurality of long fibers which have been aligned unidirectionally into an inlet at one end of a cylindrical die with a plurality of needle holes in the peripheral walls thereof, and then performing needlepunch through the needle holes while drawing the plurality of long fibers out from an outlet at the opposite end of the cylindrical die.

Unidirectional long fiber three dimensional fiber structure produced by short fiber intertwining and production method thereof

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Osaka, Japan

Tetsuro Hirokawa