Methods of co-bonding a first thermoset composite (TSC) and a second TSC to define a cured composite part are disclosed herein. The methods include partially curing the first TSC to a target state of cure (SOC) to define a first partially cured TSC. The partially curing is based, at least in part, on a maximum temperature of the first TSC during the partially curing and on an elapsed time that an actual temperature of the first TSC is greater than a threshold temperature. The methods further include combining the first partially cured TSC with the second TSC to define a partially cured TSC assembly and heating the partially cured TSC assembly to bond the first partially cured TSC to the second TSC, cure the partially cured TSC assembly, and produce a cured composite part.

A method for manufacturing a tool including assembling a stack-up that includes a plurality of precured composite laminates, the stack-up having an engagement surface, wherein each precured composite laminate of the plurality of precured composite laminates is flexible, and wherein an adhesive is positioned between adjacent precured composite laminates of the plurality of precured composite laminates, and placing the engagement surface of the stack-up onto a target surface of a substrate.

A stiffened part formed from at least two members of thermoset composite material including at least one body of a first structure and optionally a second structure. A manufacturing method includes: forming a fibre preform and impregnating each body of the first structure with thermosetting resin or forming a pre-impregnated fibre preform to obtain a body formed from uncured thermosetting composite material supported by a mandrel; optionally partially or fully polymerising at least one body supported by a mandrel; optionally, providing the second structure formed from uncured, partially uncured or fully uncured thermosetting composite material; optionally, depositing a layer of uncured thermosetting adhesive on an area where a fully cured member makes contact with another member of the part; joining the members, each member being juxtaposed with; or stacked upon, at least one other member; fully curing the assembly by heat treatment; removing the mandrel from each fully cured body.

A method forms a butt joint between ends of first and second plies and splices the first and second plies together. The method includes the steps of: positioning a first splice edge of a first ply at a first location; positioning a second splice edge of a second ply at a second location, the second splice edge being left bare; wrapping a gum strip around the first splice edge such that the first gum strip forms a U-shaped structure in section that allows the first gum strip to extend from a first planar side of the first ply over the first splice edge to a second opposite planar side of the first ply; not wrapping a gum strip around the second splice edge; placing the first splice edge in abutting relationship to the second splice edge; and stitching the first splice edge to the second splice edge such that stitches each extend from the first planar side of the first ply, through the gum strip, to the first planar side of the second ply.

A method of forming a composite member, includes: applying pressure and heat with a compaction tool to a portion of an uncured composite member to decrease a thickness of the portion, the heat applied with the compaction tool being at a temperature less than a curing temperature of the uncured composite member; and curing the uncured composite member after applying pressure and heat.

Composite laminate structures are produced using partially cured parts. Partial curing of the parts is achieved by applying a catalyst to regions of the parts that are to be fully cured. These regions cure at a lower-than-normal temperature while remaining regions of the part remain uncured, allowing them to be co-bonded or co-cured to other structures.

An object is to provide a composite pre-bonding treatment method that stabilizes quality of a bonded part. The present disclosure provides a composite pre-bonding treatment method performed when bonding a composite material to a member. The method includes: (S2) attaching an absorber adapted to absorb a contaminant to a surface of a prepreg laminate that is a precursor of the composite material; (S3) covering the prepreg laminate with a packaging material from above the absorber; (S4) vacuuming the packaging material and heating the prepreg laminate at a temperature lower than a curing temperature of a prepreg; (S5) then removing the packaging material; (S6) peeling off the absorber; (S7) attaching, to a surface of the prepreg laminate with the absorber peeled off, a release member that does not transfer silicone or fluorine to a resin, and then (S9) curing the prepreg laminate to mold the composite material; and (S11) peeling off the release member from the composite material before bonding the member.

A method of the invention produces a composite material conjugate in which a first composite material and a second composite material are adhered without using an adhesive, wherein a first prepreg laminate to which a release member is attached is cured to form the first composite material, the release member being made of a material that does not transfer silicone and fluorine to the first prepreg laminate, after detaching the release member from the first composite material, surface treatment that imparts polar functional groups to the surface of the first composite material to which the release member was bonded is carried out to activate the surface, a second prepreg laminate is placed directly on the activated surface of the first composite material, and the second prepreg laminate is cured to form a second composite material adhered to the first composite material.

A method for surface preparation of composite substrates prior to adhesive bonding. A curable surface treatment layer containing blocked isocyanate compounds is applied onto a curable composite substrate, followed by co-curing. The surface treatment layer may be a resin layer without fibers or a removal peel ply composed of resin-impregnated fabric. After surface preparation, the composite substrate is provided with a chemically-active, bondable surface that can be adhesively bonded to another composite substrate to form a covalently-bonded structure.

A shear tie connector system for securing a frame component to a composite fuselage skin, which includes a shear tie connector and a fuselage mandrel, which defines a slot within which the shear tie connector is positioned.