There is provided a method for producing a metal-resin composite which includes a resin member and a metal member having a roughened surface in at least a portion of the surface thereof, the resin member being joined so as to be in contact with at least a portion of the roughened surface. The method includes a step of joining the resin member and the metal member by melting the resin member with the frictional heat generated in the surface of the metal member on its side opposite to the resin member in a state where the metal member and the resin member are superposed. The method includes making adjustment so that when the roughened surface is measured at arbitrary five points by using a confocal microscope according to ISO 25178, the developed area ratio (Sdr) is 5 or more in terms of number-average value.

There is provided a method for producing a metal-resin composite which includes a resin member and a metal member having a roughened surface in at least a portion of the surface thereof, the resin member being joined so as to be in contact with at least a portion of the roughened surface. The method includes a step of joining the resin member and the metal member by melting the resin member with the frictional heat generated in the surface of the metal member on its side opposite to the resin member in a state where the metal member and the resin member are superposed. The method includes making adjustment so that when the roughened surface is measured at arbitrary five points by using a confocal microscope according to ISO 25178, the developed area ratio (Sdr) is 5 or more in terms of number-average value.

A method for manufacturing a wind turbine blade includes the use of an apparatus having an engagement part. The engagement part has: a support element having a first support edge and a second support edge, a belt extending around the support element and forming a primary engagement edge of the engagement part along the first support edge of the support element. The method includes: providing one or more pre-shaped elements, including a first pre-shaped element, in a first element position, positioning the engagement part in a first position, moving the support element in a first direction with a first velocity to extend underneath the first pre-shaped element, and at the same time moving the belt relative to the support element around the first support edge in a primary direction from below the first support edge to above the first support edge with a primary velocity.

A fiber-reinforced resin composite sheet of the present invention contains: a polyamide resin film containing a dicarboxylic acid component (a) and a diamine component (b); and a plurality of reinforcing fibers laminated in a state of being oriented in the same direction on the polyamide resin film, the reinforcing fibers being obtained by opening a reinforcing fiber bundle. The dicarboxylic acid component (a) contains 60 mol % or more and 100 mol % or less of terephthalic acid. The diamine component (b) contains 60 mol % or more and 100 mol % or less of 1,9-nonanediamine and 2-methyl-1,8 octanediamine. The fiber-reinforced resin composite sheet has a volume content rate Vf of the reinforcing fibers of 20% or more and 70% or less and a thickness of 20 μm or more and 70 μm or less.

A fiber reinforced resin hollow molded body 30 in which a resin-integrated fiber sheet is used. The resin-integrated fiber sheet includes unidirectional continuous fibers that are spread fibers of a continuous fiber group and arrayed unidirectionally in parallel, and thermoplastic resin that is present at least on a surface of the unidirectional continuous fibers. In the hollow molded body, in a state where the resin-integrated fiber sheet or a plurality of the resin-integrated fiber sheets 30 are stacked, the resin-integrated fiber sheet or the plurality of resin-integrated fiber sheets are wound to produce a wound body having an overlapping portion. The thermoplastic resin is impregnated in the unidirectional continuous fibers. The resin-integrated fiber sheet or the plurality of resin-integrated fiber sheets are consolidated.

The method involves supplying a profile which is wound round a winding structure (13). The stresses are present in the profile as a result of the winding. The profile comprises several fibers extending along one another, which are embedded in a partially cured thermosetting matrix material. A heat treatment is carried out on the profile, by means of a heat treatment device, while the profile is wound round the winding structure. The matrix material is post-cured, during heat treatment. The glass-transition temperature of the matrix material is increased as a result of the heat treatment and the temperature to which the profile is exposed during the heat treatment remains below the glass-transition temperature. The stresses remain constant and the shape is retained both in cross-section as well as radius of curvature of the profile, in the stress-free state, despite the heat treatment and despite winding the profile round the winding structure prior to the heat treatment.

The invention provides a sonotrode (100) for welding a material, the sonotrode (100) comprising a welding section (110) configured for contacting the material, wherein the welding section (110) defines a rounded shape (111) in a cross-section parallel to a longitudinal axis (A) of the sonotrode (100), wherein the rounded shape (111) approximates a circular sector (20), wherein the circular sector (20) has a central angle α.sub.c selected from the range of 25°-300°, and wherein the circular sector (20) has a central radius r.sub.c selected from the range of 5-30 mm, and wherein the sonotrode (100) has a width W perpendicular to the longitudinal axis (A) [and to the cross-section], wherein W is selected from the range of 10-100 mm.

The invention provides a sonotrode (100) for welding a material, the sonotrode (100) comprising a welding section (110) configured for contacting the material, wherein the welding section (110) defines a rounded shape (111) in a cross-section parallel to a longitudinal axis (A) of the sonotrode (100), wherein the rounded shape (111) approximates a circular sector (20), wherein the circular sector (20) has a central angle α.sub.c selected from the range of 25°-300°, and wherein the circular sector (20) has a central radius r.sub.c selected from the range of 5-30 mm, and wherein the sonotrode (100) has a width W perpendicular to the longitudinal axis (A) [and to the cross-section], wherein W is selected from the range of 10-100 mm.

The present invention discloses a foldable FRP plate, comprising a plurality of first regions and one or a plurality of second regions which are integrated in one piece; the second region is located between two adjacent first regions, so that the adjacent first regions being folded and unfolded relative to each other with the second region as a rotating shaft; the first regions are plate-like products manufactured by impregnating fiber woven fabric with resin for curing, are rigid and cannot be folded; the second region is flexible fiber woven fabric and has a width being two times a design thickness of the FRP plate. The present invention also discloses a manufacturing method, including laying the fiber woven fabric according to a design thickness and a layer layout; dividing the first regions and the second region according to an origami design method.

A method of fabricating a fiber structure by multilayer three-dimensional weaving between a plurality of weft yarns and of warp yarns, the fiber structure having at least first and second portions that are adjacent in the warp direction, the first portion presenting, in a direction perpendicular to the warp and weft directions, a thickness greater than the thickness of the second portion, includes making the first portion using a step of three-dimensionally weaving warp and weft layers in which a fiber fabric is formed in the form of a Mock-Leno weave grid in a core of the first portion together with skins at a surface of the first portion, a weave of the skins being modified locally so as to deflect certain warp yarns from said skins and weave them with the fiber fabric in the form of the Mock-Leno weave grid.