The present disclosure relates to a spar cap (10) for a wind turbine blade (1000) comprising: a plurality of spar cap layers (20) and a first interlayer (30) arranged between the first spar cap layer (20a) and the second spar cap layer (20b) and comprising: a number of first interlayer areas (31), including a first primary interlayer area (31a), comprising a first number of interlayer sheets (33) comprising a first plurality of fibres (35); and a number of second interlayer areas (32), including a second primary interlayer area (32a), comprising a second number of interlayer sheets (34) comprising a second plurality of fibres (36), wherein the first number of interlayer sheets (33) is of a different characteristic than the second number of interlayer sheets (34).

A method for bonding composite substrates includes coupling a first co-cure prepreg layer having a first off-set amine to epoxide molar ratio onto a surface of a first composite substrate and coupling a second co-cure prepreg layer having a second off-set amine to epoxide molar ratio onto a surface of a second composite substrate. The first and second composite substrates are cured to the first and second co-cure prepreg layers, respectively, using a first cure cycle (including B-stage and cure temperatures) to form a first and a second co-cure prepreg layer portion. The method further includes coupling the first co-cure prepreg layer portion to the second co-cure prepreg layer portion and applying a second cure cycle to cure the first co-cure prepreg layer portion of the first composite substrate to the second co-cure prepreg layer portion of the second composite substrate to form a monolithic covalently bonded composite structure.

A method for producing a fiber composite laminate, including the steps of applying pressure and/or heat to a first preform, which has one or more dry fiber layers and a thermoplastic elastomer, such that the thermoplastic portion of the thermoplastic elastomer completely impregnates the dry fiber layers of the first preform in at least one first region and only partially impregnates the dry fiber layers in at least one second region and, in a thermosetting polymer matrix, impregnating and curing the fiber layers of the second region of the first preform that are still dry and have not been impregnated with the thermoplastic portion of the thermoplastic elastomer.

A method for manufacturing an outer skin of a rotor blade includes forming an outer skin layer of the outer skin from a first combination of at least one of one or more resins or fiber materials. The method also includes forming an inner skin layer of the outer skin from a second combination of at least one of one or more resins or fiber materials. More specifically, the first and second combinations are different. Further, the method includes arranging the outer and inner skin layers together in a stacked configuration. In addition, the method includes joining the outer and inner skin layers together to form the outer skin.

A fiber preform is infused with two differing resin systems concurrently using stacked resin delivery assemblies located along one edge of the preform.

A fiber-reinforced member includes: a base member having a tubular region with an outer circumferential surface extending along and substantially in parallel with an axial direction; and a fiber-reinforced resin layer constituted of a tow prepreg wound in an overlapping manner to cover the outer circumferential surface of the base member along a predetermined direction crossing the axial direction when viewed in a radial direction of the base member, the tow prepreg serving as a widened tape-like member. The tape-like member constituting the fiber-reinforced resin layer has a portion having a fiber line extending along a direction crossing the predetermined direction. A size of a width of the tape-like member constituting the fiber-reinforced resin layer is not less than 100 times and not more than 400 times as large as a size of a thickness of the tape-like member constituting the fiber-reinforced resin layer in the radial direction.

A hybrid fiber-reinforced composite material according to an aspect of the present disclosure may comprise a first continuous fiber layer, a long fiber layer laminated on one surface of the first continuous fiber layer, and a second continuous fiber layer laminated on one surface of the long fiber layer, and may further comprise at least one of a first thermosetting resin laminated on the other surface of the first continuous fiber layer and a second thermosetting resin laminated on one surface of the second continuous fiber layer.

Provided is a cold press molded body having excellent fastening strength and fastening stability as well due to the use of a discontinuous carbon fiber and a discontinuous glass fiber for adjusting the volume, preferably the volume resistivity, of an end region (flowing region).

Disclosed are reinforced structures. The structures are comprised of reinforced elements that have continuous fibers embedded in a matrix material. The reinforced elements are combined in a matrix material to form a desired shape of reinforced structure.

An object of the present invention is to provide a prepreg and a laminate for producing a laminate suitable as a structural material, which have excellent joining strength and can be firmly integrated with another structural member by welding. The present invention provides a prepreg including the following structural components: [A] reinforcing fibers, [B] a thermosetting resin, and [C] a thermoplastic resin, wherein [A] has a surface free energy, measured by a Wilhelmy method, of 10 to 50 mJ/m.sup.2, [C] is present on a surface of the prepreg, and the reinforcing fibers [A] are present, which are included in a resin area including [B] and a resin area including [C] across an interface between the two resin areas.