The present invention relates to resin compositions, fiber reinforced polymeric structures and electromagnetic induction processes for making same. Such magnetic induction processes are pulsed processes that can be optionally coupled with cooling steps between pulses. The aforementioned fiber reinforced polymeric structures can take forms that include, but are not limited to, pipes; pressure vessels, including rocket motor cases and fire extinguishers; golf club shafts; tennis and badminton racquets; skis; snowboards; hockey sticks; fishing rods; bicycle frames; boat masts; oars; paddles; baseball bats; and softball bats. In addition, such fiber reinforced polymeric structures can be supplemented with other materials, such as a rocket propellant, to form articles, for example, a rocket motor.

A method of offset load testing a tubular composite specimen with two pairs of aligned holes and having at least one defect, the method comprising: providing a testing apparatus having a pair of arms including a fixed arm and a mobile arm; securing the pair of arms using a fastener assembly in each of the two pairs of aligned holes; and moving the mobile arm to impart an offset load force to the tubular specimen. One aspect includes a method of offset load testing comprising: providing a testing apparatus having a pair of arms including a fixed arm and a mobile arm; providing a tubular composite specimen with a top portion and a bottom portion; securing the pair of arms to the top and bottom portions of the tubular composite specimen; and moving the mobile arm to impart an offset load force to the tubular composite specimen.

A method of offset load testing a tubular composite specimen with two pairs of aligned holes and having at least one defect, the method comprising: providing a testing apparatus having a pair of arms including a fixed arm and a mobile arm; securing the pair of arms using a fastener assembly in each of the two pairs of aligned holes; and moving the mobile arm to impart an offset load force to the tubular specimen. One aspect includes a method of offset load testing comprising: providing a testing apparatus having a pair of arms including a fixed arm and a mobile arm; providing a tubular composite specimen with a top portion and a bottom portion; securing the pair of arms to the top and bottom portions of the tubular composite specimen; and moving the mobile arm to impart an offset load force to the tubular composite specimen.

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.

A method for manufacturing a structural element for a fuselage of an aircraft. To improve the manufacture of structural elements, a method includes laying up textile material members on a mandrel to form a plurality of structural element preforms that are space apart along an extended direction of the mandrel. The structural element preforms form closed loops and are subsequently cured to obtain annular structural elements. The annular structural elements are used as basic building blocks for stiffening panel members or are directly used as structural frame elements reinforcing cut-outs in a fuselage for windows and/or doors.

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 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.

A gas turbine fan casing made of composite material with a fibrous reinforcement includes a plurality of superimposed turns of a strip-shaped fibrous texture having a three-dimensional weaving between a plurality of layers of warp yarns and a plurality of layers of weft yarns, the fibrous reinforcement being densified by a matrix. The fibrous texture includes at least one lateral section of variable thickness in which the weft yarns have a size or a count different from the size or the count of the weft yarns of the plurality of layers of weft yarns present in the remainder of the fibrous texture.

A gas turbine fan casing made of composite material with a fibrous reinforcement includes a plurality of superimposed turns of a strip-shaped fibrous texture having a three-dimensional weaving between a plurality of layers of warp yarns and a plurality of layers of weft yarns, the fibrous reinforcement being densified by a matrix. The fibrous texture includes at least one lateral section of variable thickness in which the weft yarns have a size or a count different from the size or the count of the weft yarns of the plurality of layers of weft yarns present in the remainder of the fibrous texture.

A system includes a mandrel contoured to define a tapering tubular shape of a workpiece cured on the mandrel and a demolding tool. The demolding tool is configured to remove the workpiece from the mandrel after the workpiece is cured on the mandrel and cut longitudinally. The demolding tool is configured to remove the workpiece from the mandrel by deforming a first end of the workpiece to at least partially disengage the first end of the workpiece from a first end of the mandrel, and subsequently, deforming a second end of the workpiece to at least partially disengage the second end of the workpiece from a second end of the mandrel. The first end of the workpiece may have a first cross-sectional area that is smaller than a second cross-sectional area of the second end of the workpiece.