Abstract: Systems and methods are provided for fabricating multiple segment spars for an aircraft. In one example the method includes fabricating preforms of fiber reinforced material for spar segments, hardening the preforms to form the spar segments, and bonding the spar segments together to form a completed spar detail. In addition to bonding, other examples include co-curing and fastening the spar segments. In additional examples, the spar segments include kinks or sub-kinks as described.

Abstract: An example aircraft wing includes a first skin, a second skin opposite to the first skin, and a composite spar. The composite spar includes a double-flanged spar cap, a single-flanged spar cap, a spar web connecting the double-flanged spar cap and the single-flanged spar cap, and a tear strap. The double-flanged spar cap includes an inward-facing flange and a first outward-facing flange, and the inward-facing flange and the first outward-facing flange are integrated with the first skin during a co-curing process. The single-flanged spar cap includes a second outward-facing flange that is attached to the second skin. The tear strap is stitched to an inner side of the spar web along at least a portion of a length of the composite spar.

Abstract: An example aircraft wing includes a first skin, a second skin opposite to the first skin, and a composite spar. The composite spar includes a double-flanged spar cap, a single-flanged spar cap, a spar web connecting the double-flanged spar cap and the single-flanged spar cap, and a tear strap. The double-flanged spar cap includes an inward-facing flange and a first outward-facing flange, and the inward-facing flange and the first outward-facing flange are integrated with the first skin during a co-curing process. The single-flanged spar cap includes a second outward-facing flange that is attached to the second skin. The tear strap is stitched to an inner side of the spar web along at least a portion of a length of the composite spar.

Abstract: Provided are wingtip torque boxes and methods of fabricating such boxes using friction stir welding. Specifically, a wingtip torque box may be formed by friction stir welding two monolithic clamshells along their respective spars thereby forming a new monolithic structure. Use of the friction stir welding and monolithic clamshells simplifies the overall fabrication process and yields a robust wingtip torque box that can be bolted on or otherwise attached to an aircraft wing. The wingtip torque box may include internal grid stiffeners and/or external stiffeners that may be also monolithic with other components of the box. For example, the stiffeners may be machined in spars or skin portions of the clamshells during fabrication of clamshells. The wingtip torque box may have a continuous cavity extending between the ends and, in some embodiments, between spars of the box and providing access for performing various operations inside the box.

Abstract: Provided are wingtip torque boxes and methods of fabricating such boxes using friction stir welding. Specifically, a wingtip torque box may be formed by friction stir welding two monolithic clamshells along their respective spars thereby forming a new monolithic structure. Use of the friction stir welding and monolithic clamshells simplifies the overall fabrication process and yields a robust wingtip torque box that can be bolted on or otherwise attached to an aircraft wing. The wingtip torque box may include internal grid stiffeners and/or external stiffeners that may be also monolithic with other components of the box. For example, the stiffeners may be machined in spars or skin portions of the clamshells during fabrication of clamshells. The wingtip torque box may have a continuous cavity extending between the ends and, in some embodiments, between spars of the box and providing access for performing various operations inside the box.

Abstract: A rib is disclosed for use in a torque box of a wing structure provided on an aircraft. The wing structure has a skin panel and a stringer coupled to the skin panel. The rib includes a web defining at least one stringer hole sized to receive the stringer, a shear tie coupled to the web and configured to engage the skin panel, and a clip positioned adjacent the at least one stringer hole. The clip has a base coupled to and aligned with the web, a head extending at an angle relative to the base and configured to engage the stringer, and a transition portion extending between the base and the head.

Abstract: A rib is disclosed for use in a torque box of a wing structure provided on an aircraft. The wing structure has a skin panel and a stringer coupled to the skin panel. The rib includes a web defining at least one stringer hole sized to receive the stringer, a shear tie coupled to the web and configured to engage the skin panel, and a clip positioned adjacent the at least one stringer hole. The clip has a base coupled to and aligned with the web, a head extending at an angle relative to the base and configured to engage the stringer, and a transition portion extending between the base and the head.