The present invention relates to stretched polyolefin fibers comprising a polymer comprising at least one polymeric modifier selected from olefinic polymers modified with an acid and/or an acid anhydride, the use of these fibers in the reinforcement of cementitious compositions, and cementitious composition containing these fibers.

Provided is a commingled yarn having a dispersing property and having a smaller amount of voids, a method for manufacturing the commingled yarn, and a weave fabric using the commingled yarn. The commingled yarn comprises a continuous thermoplastic resin fiber, a continuous reinforcing fiber, and a surface treatment agent and/or sizing agent, comprises the surface treatment agent and/or sizing agent in a content of 2.0% by weight or more, relative to a total amount of the continuous thermoplastic resin fiber and the continuous reinforcing fiber, and has a dispersibility of the continuous thermoplastic resin fiber and the continuous reinforcing fiber of 70% or larger.

A tubular structure having lobes is produced as a single piece over at least two lobes. Circumferential fibres of the structure have a constant orientation with respect to the longitudinal axis (A) of the structure in any plane (P) transverse to the longitudinal axis. The structure is obtained by weaving or by filament winding.

A fibrous structure includes a main plate and a sub-plate. The main plate, which is formed by a multi-layer textile, includes a plurality of stacked fiber layers. Each fiber layer includes main plate warps and main plate wefts. The sub-plate, which is formed by a multi-layer textile, includes a plurality of stacked fiber layers. Each fiber layer includes sub-plate warps and sub-plate wefts. The main plate and the sub-plate are integrally woven with each other in a state intersecting each other. The main plate wefts and the sub-plate wefts have a smaller volume density at an intersecting portion where the main plate and the sub-plate intersect than a portion separate from the intersecting portion.

A knitting method and an apparatus for a cylindrical biaxial weft-knitted three-dimensional knitted structure. The biaxial three-dimensional knitted structure comprises two weft plain stitch structures (7, 7′), a group of spacer yarns (416), two groups of weft inserting yarns (415, 415′) and a group of warp inserting yarns (43), wherein the two groups of weft inserting yarns are used for selective weft inserting on a needle dial (11) or a needle cylinder (13), the warp inserting yarns are positioned between the two groups of weft inserting yarns, the two weft plain stitch structures are connected with each other by the group of spacer yarns, for jointly clamping the weft inserting yarns and the warp inserting yarns, in order to form a biaxial weft-knitted three-dimensional knitted structure. Such three-dimensional knitted structure improves the mechanical properties of three-dimensional knitted fabrics; by increasing the interval between the needle dial and the needle cylinder, the thickness of the knitted structure is increased, which is suitable for the reinforced structure of high-performance structural and functional composite materials, and expand the field of the use of the knitted structures.

A bionic nested structure fiber composite material includes a first fiber resin layer and a second fiber resin layer which are arranged in parallel, the first fiber resin layer and the second fiber resin layer are formed by a fiber bundle infiltrated with resin, and a bonded fiber unit is arranged between the first fiber resin layer and the second fiber resin layer, the bonded fiber unit are evenly distributed in a radial direction and a weft direction, the bonded fiber unit includes an inner core layer bonded fiber bundle, a middle core layer bonded fiber bundle and an outer core layer bonded fiber bundle, and the bonded fiber unit is performed 3D integrated layer-by-layer inner and outer nesting-and-weaving to form bionic nested structure.

A multi-layer braided article and a method of making the multi-layer braided article. The multi-layer braided article includes a braid extending along a first axis, wherein the braid is folded over itself to form a first layer and a second layer; and a wrapper laid over the first layer of the braid and extending circumferentially around the first axis, wherein the wrapper defines an edge of the first layer about which the braid is folded. The multi-layer braided article may form part of a blade for an aircraft. A sleeve may be provided around a conical portion of the article to connect the article to something else, such as a propeller hub, where the multi-layer braided article is formed as part of a blade. The sleeve may provide a primary or secondary load path.

A vane includes a fiber reinforcement having a three-dimensional weaving densified by a matrix, the fiber reinforcement including in a single woven part a root portion and an airfoil portion extending along a longitudinal direction between the root portion and a vane tip portion and along a transverse direction between a leading edge portion and a trailing edge portion. The airfoil portion includes first and second extrados and intrados faces. The fiber reinforcement includes a non-interlinking forming a housing inside the fiber reinforcement, a conformation part being present in the housing. The non-interlinking extends over a non-interlinked area inside the airfoil portion of the fiber reinforcement included between the root portion and the vane tip portion in the longitudinal direction and between the leading edge portion and the trailing edge portion in the transverse direction, the non-interlinking also opening outside the airfoil portion of the fiber reinforcement.

A method produces a fiber composite preform for a fiber composite component. The fiber composite preform has a plurality of layers of a fiber roving. The method includes: providing a support core for arranging the fiber roving s on a braiding device, the support core having a support core longitudinal axis, producing a first braided fabric layer from fiber rovings on the support core in a first braiding direction parallel to the support core longitudinal axis of the support core by the braiding device, and producing a second braided fabric layer from fiber rovings on the first braided fabric layer by the braiding device. The second braided fabric layer is produced in a second braiding direction parallel to the support core longitudinal axis, the second braiding direction being opposite the first braiding direction.

Some embodiments are directed to a preform including reinforcing fibres and shape memory alloy (SMA) wires, a composite material including a polymer matrix with a preform embedded therein, articles including a composite material, methods of making preforms, composite materials and articles.