Abstract: A method of forming a direct bearing joint includes coupling a first load-bearing structure to a second load-bearing structure. The second load-bearing structure includes a first structural feature comprising a first arcuate shape. The method also includes coupling a composite skin including a second structural feature comprising a second arcuate shape to the second load-bearing structure. The composite skin is coupled to the second load-bearing structure such that the first and second structural features are mated against each other to facilitate distributing compressive loads from the second load-bearing structure into the composite skin.

Abstract: A method of forming a direct bearing joint includes providing a load bearing structure including a first structural feature having an arcuate shape and providing a composite skin including a second structural feature also having an arcuate shape. The method also includes coupling the first structural feature to the second structural feature such that the first and second structural features are mated against each other to facilitate distributing compressive loads induced into the load bearing structure into the composite skin.

Abstract: Anisotropic pressure panels are disclosed. The pressure panels include at least two distinct regions, with one region yielding to lateral deformation more than at least one other region. The regions each independently may include a plurality of beads, such beads optionally integrally formed in the body of the pressure panel. In aerospace applications, the pressure panel may be coupled to load-bearing structures, such as wings, and may at least partially define a wheel well.

Abstract: A method of forming a direct bearing joint includes providing a load bearing structure including a first structural feature having an arcuate shape and providing a composite skin including a second structural feature also having an arcuate shape. The method also includes coupling the first structural feature to the second structural feature such that the first and second structural features are mated against each other to facilitate distributing compressive loads induced into the load bearing structure into the composite skin.

Abstract: Fuselages according to the present disclosure include a structural frame and a skin operatively coupled to the structural frame. In some embodiments, the skin includes a plurality of core sections that extend circumferentially around the fuselage and that are spaced-apart longitudinally along the fuselage. In some embodiments, the inner side of the skin generally undulates longitudinally along the fuselage. Methods of constructing fuselages also are disclosed.

Abstract: The disclosed shell structure splice and method may include a first panel having a first edge, a second panel having a second edge, the second edge being positioned in edgewise alignment with the first edge to form a splice joint, a strap bridging the splice joint and attached to the first panel and the second panel, the strap having a first tapered region and a second tapered region, a first fitting having a tapered section and a flat section, the tapered section being attached to the first tapered region of the strap, and a second fitting having a tapered section and a flat section, the tapered section being attached to the second tapered region of the strap.

Abstract: A fuselage having a longitudinal window belt has a composite outer skin including upper and lower composite skin sections. The skin includes at least one window opening located at the window belt. The upper and lower skin sections are joined together by a longitudinal splice joint located at the window belt.

Abstract: Anisotropic pressure panels are disclosed. The pressure panels include at least two distinct regions, with one region yielding to lateral deformation more than at least one other region. The regions each independently may include a plurality of beads, such beads optionally integrally formed in the body of the pressure panel. In aerospace applications, the pressure panel may be coupled to load-bearing structures, such as wings, and may at least partially define a wheel well.

Abstract: A pressure bulkhead may include a bulkhead wall having a radially inner disk and a radially outer compression ring, the outer compression ring being reinforced to balance meridional and hoop stresses sustained by the bulkhead wall in response to a pressure differential across the pressure bulkhead; and the radially inner disk being unitary with the outer compression ring and being made of the same material as the outer compression ring.

Abstract: Systems, tools, and methods for forming composite tubular stringers and stiffened composite structures having composite tubular stringers are disclosed. Systems include a tool, a supply of pliable blanks for forming composite tubular stringers with the tool, a supply of skin segments for forming a skin, and a layup mandrel for receiving the composite tubular stringers and the skin to form a stiffened composite structure. Tools include a wrapping mandrel for forming from a pliable blank a tubular structure with a first circumferential profile, and a transition mandrel for conforming the tubular structure to a second circumferential profile. Methods include wrapping a pliable blank around a wrapping mandrel to define a tubular structure having a first circumferential profile, and transitioning the tubular structure from having the first circumferential profile to having a second circumferential profile.

Abstract: A fuselage having a longitudinal window belt has a composite outer skin including upper and lower composite skin sections. The skin includes at least one window opening located at the window belt. The upper and lower skin sections are joined together by a longitudinal splice joint located at the window belt.

Abstract: A stringer having a stringer end trim that reduces pull-off forces in a stringer connection structure, including a stringer body; a stringer free edge provided on said stringer body; and a stringer end trim having at least one curvature provided in the stringer free edge forming the stringer connection structure.

Abstract: A finite element method for predicting crack opening and propagation entails defining a succession of overlapping interface elements at a potential crack plane, each element having a bound node pair and side node pairs spaced from the bound node pair to sense approach of a crack. An energy-based fracture mechanics criterion determines whether release occurs at the bound nodes and, if so, the displacement between the bound nodes is calculated based on a strain softening law. The process is repeated for each element in sequence.

Abstract: A composite resin window frame for installation in a composite resin airplane fuselage has an inner flange for receiving and securely affixing an aircraft window transparency and an outer flange adapted for connection to the airplane fuselage structure. The frame has a generally flat configuration which does not require any additional strength enhancing member such as an additional flange perpendicular to the structure. The composite resin window frame has sufficient strength to securely affix a window transparency to a composite resin fuselage.

Abstract: A finite element method for predicting crack opening and propagation entails defining a succession of overlapping interface elements at a potential crack plane, each element having a bound node pair and side node pairs spaced from the bound node pair to sense approach of a crack. An energy-based fracture mechanics criterion determines whether release occurs at the bound nodes and, if so, the displacement between the bound nodes is calculated based on a strain softening law. The process is repeated for each element in sequence.

Abstract: A cargo barrier net for an aircraft includes a central ring. A plurality of radially projecting webs include a radially inner end that is connected to the central ring. A radially outer end is connected to the airframe. The first circumferential web is connected to a first set of mid-portions of the radially projecting webs. A first set of mid-portions is located radially outside of the central ring. A second circumferential web is located radially outside of the first circumferential web. The second circumferential web is connected to a second set of mid-portions of the radially projecting webs. The second set of mid-portions is located radially outside of the first set of mid-portions. A third circumferential web is located radially outside of the second circumferential web. The third circumferential web is connected to a third set of mid-portions of the radially projecting webs. The third set of mid-portions is located radially outside of the second set of mid-portions.