Method and apparatus for fabricating reformable stiffening elements
A stiffening element comprises a tension and compression member, a shear member, an attachment member, and a plurality of beads. The tension and compression member is positioned spaced apart from the skin and configured to bear tension or compression forces that stiffen the skin and prevent the skin from buckling or bending. The shear member is connected to the tension and compression member and configured to bear shear forces between the skin and the tension and compression member. The attachment member is connected to the shear member and is configured to connect to the skin. The beads each create out-of-plane feature that is positioned in at least one of the shear member and the attachment member. The beads permit the stiffening element be reshaped to adjust a longitudinal curvature of the stiffening element.
1. A stiffening element to be attached to a skin of aircraft components for providing structural reinforcement, the stiffening element comprising:
a tension and compression member positioned spaced apart from the skin and configured to bear tension or compression forces that stiffen the skin and prevent the skin from buckling or bending;
a shear member connected to the tension and compression member and configured to bear shear forces between the skin and the tension and compression member;
an attachment member connected to the shear member and configured to connect to the skin; and
a plurality of beads, each bead creating an out-of-plane feature that is positioned in at least one of the shear member and the attachment member, at least one of the plurality of beads configured to be reshaped to adjust a longitudinal curvature of the stiffening element.
2. The stiffening element of claim 1 , wherein
the shear member includes a first shear member connected to a first edge of the attachment member and a second shear member connected to a second edge of the attachment member, and
the tension and compression member includes a first tension and compression member connected to the first shear member and a second tension and compression member connected to the second shear member.
3. The stiffening element of claim 2 , wherein each bead starts near an edge of the first shear member adjacent to the first tension and compression member, extends in a transverse direction across the first shear member, extends into and across the entire width of the attachment member, extends in a transverse direction across the second shear member, and ends near an edge of the second shear member adjacent to the second tension and compression member.
4. The stiffening element of claim 1 , wherein
the shear member includes a first shear member connected to a first edge of the tension and compression member and a second shear member connected to a second edge of the tension and compression member, and
the attachment member includes a first attachment member connected to the first shear member and a second attachment member connected to the second shear member.
5. The stiffening element of claim 4 , wherein the plurality of beads includes a plurality of beads formed in each of the first and second attachment members.
6. The stiffening element of claim 1 , wherein each bead has an arch or roughly parabolic cross-sectional shape.
7. The stiffening element of claim 1 , wherein each bead is configured to be reshaped in a first manner to adjust the longitudinal curvature of the stiffening element in a first direction and reshaped in a second manner to adjust the longitudinal curvature of the stiffening element in a second direction, opposite to the first direction.