Patent ID: 8640428

Claim:
Insert assembly of high specific strength for sandwich structures comprising: (a) an arrangement of components including: i. an attachment; ii. a one-piece insert, which circumferentially surrounds the attachment; iii. potting material, which circumferentially surrounds the insert; and iv. a core, which circumferentially surrounds the potting material, (b) an upper face-plate located on an upper surface of the arrangement; and (c) a lower face-plate located on a lower surface of the arrangement, wherein the insert is a 3D woven composite that comprises a 3D preform and that is made using the 3D preform and resin transfer molding, wherein the 3D preform is a fully integrated continuous fiber assembly having multiaxial in-plane and out-of-plane fiber orientations, and reinforcement provided in through-the-thickness and planar directions, that is made using a 3D weaving process, wherein the 3D woven composite is selected from the group consisting of: 3D thermoelastic isotropic woven composites wherein elastic and thermal properties are the same along all directions; 3D orthogonal or angle interlock woven orthotropic composites; 3D woven composites with multiple inserts, each insert having different elastic and strength properties; 3D functionally gradient woven composites, which have gradually varying elastic and strength properties along a radial direction; and combinations thereof, wherein the insert assembly, which has high specific strength, has little or no stress concentration at interfaces between the attachment and the insert, between the insert and the potting material and between the potting material and the core.