Hybrid composite structure having damped metallic fibers and method for making the same

Abstract

A damped composite structure is formed from a matrix material and a plurality of shape memory alloy wire fibers held in the material matrix for damping the structure. The wire fibers may be embedded in a viscoelastic interlayer to increase damping of the structure. The wire fibers may be interspersed with reinforcement such as carbon fibers, in tows or in a mesh of fibers. The wire fibers have an inherent material loss factor greater than approximately 0.10, and may be formed from superelastic metal alloys, such as Ni—Ti, Cu—Zn—Al, Cu—Al—Ni, OR Cu—Al—Be.

1 - 20 . (canceled) 
     
     
         21 . A method of fabricating a damped composite structure for aircraft, comprising the steps of:
 introducing shape memory alloy wire fibers into plies of fiber reinforced synthetic resin; and   laminating the plies.   
     
     
         22 . The method of  claim 21 , wherein the step of laminating the plies includes:
 laying up multiple fiber reinforced plies of synthetic resin having the wire fibers introduced therein,   compacting the plies of the layup, and   curing the compacted layup.   
     
     
         23 . The method of  claim 21 , wherein the step of introducing shape memory alloy wire fibers includes forming tows of reinforcing fibers containing the wire fibers. 
     
     
         24 . The method of  claim 21 , wherein the step of introducing shape memory alloy wire fibers includes forming a tape including the wire fibers and reinforcing fibers. 
     
     
         25 . The method of  claim 21 , wherein the multiple fiber reinforced plies include a layer of viscoelastic material and the wire fibers are embedded in the viscoelastic material 
     
     
         26 . The method of  claim 25 , wherein the layer of viscoelastic material is contained in a layer of resin. 
     
     
         27 . The method of  claim 26 , wherein the wire fibers extend from the layer of viscoelastic material into the layer of resin. 
     
     
         28 . The method of  claim 22 , wherein the step of layup up multiple fiber reinforced plies of synthetic resin comprises arranging the wire fibers as a mesh 
     
     
         29 . The method of  claim 21 , further comprising:
 carbon fibers reinforcing the material matrix, and   
     
     
         30 . The method of  claim 29 , wherein:
 the carbon fibers are arranged in a plurality of tows, and   the wire fibers are contained within the tows.   
     
     
         31 . The method of  claim 21 , wherein the shape memory alloy is selected from the group consisting of: Ni—Ti, Cu—Zn—Al, Cu—Al—Ni, Cu—Al—Be. 
     
     
         32 . The method of  claim 31 , wherein the shape memory alloy includes one of: Nb, Fe and Pt. 
     
     
         33 . The method of  claim 21 , wherein the shape memory alloy is selected from the group consisting of: Fe—C—Si, Al—Zn, Fe—Cr, Fe—Cr—Al, Co—Ni—Ti, Mg, Fe, Ni, Mg—Ni, Mn—Cu, Mn—Cu-AL, CU-Zn—Al, CU-Al, Ni, Ni—Ti, and Fe—Co. 
     
     
         34 . The method of  claim 21 , wherein the wire fibers exhibit an inherent material loss factor greater than approximately 0.10. 
     
     
         35 . A method of fabricating a damped composite structure for aircraft, comprising the steps of:
 providing a matrix material comprising a resin and a plurality of reinforcement fibers; and   introducing a plurality of metallic shape memory alloy wire fibers into the matrix material.   
     
     
         36 . The method of fabricating the damped composite structure of  claim 35 , wherein the plurality of matrix material comprises a plurality of plies; and further comprising laminating the plurality of plies. 
     
     
         37 . The method of fabricating the damped composite structure of  claim 35 , wherein the material matrix includes a layer of viscoelastic material and the wire fibers are embedded in the viscoelastic material. 
     
     
         38 . The method of fabricating the damped composite structure of  claim 35 , wherein the material matrix includes a layer of resin and the layer of viscoelastic material is contained in the layer of resin. 
     
     
         39 . The method of fabricating the damped composite structure of  claim 37 , wherein the wire fibers extend from the layer of viscoelastic material into the layer of resin. 
     
     
         40 . The method of fabricating the damped composite structure of  claim 35 , further comprising arranging the wire fibers as a mesh.