Method of making a composite laminate having a damping interlayer

Abstract

Composite laminates used in structural applications include an interlayer of soft material that provides damping action to reduce noise and vibration. The interlayer may comprise a viscoelastic material which deforms under stress caused by shock, noise or vibration. A reinforcement may be embedded in the viscoelastic material to maintain the mechanical strength and stiffness of the laminate. The reinforcement may include individual or woven fibers or ridged tubes that provide the interlayer with stiffness.

1 - 26 . (canceled) 
     
     
         27 . A method of making a damped composite laminate structure, comprising the steps of:
 (A) introducing a reinforcement medium into a layer of damping material;   (B) placing the layer of damping material between first and second layers of fiber reinforced resin material; and,   (C) co-curing the layer of damping material with the first and second layers.   
     
     
         28 . The method of  claim 27 , wherein step (C) includes compressing the first and second layers and the layer of damping material. 
     
     
         29 . The method of  claim 27 , wherein step (B) includes:
 attaching the layer of damping material to the first layer, and   then, applying the second layer over the layer of damping material.   
     
     
         30 . The method of  claim 27 , wherein step (A) includes mixing reinforcing inclusions into a liquid viscoelastic material. 
     
     
         31 . The method of  claim 27 , wherein step (A) includes infusing the reinforcement medium with a viscoelastic material. 
     
     
         32 . The method of  claim 27 , wherein step (A) includes:
 providing a web of synthetic reinforcing fibers, and,   pressing a film of viscoelastic material onto the web.   
     
     
         33 . The method of  claim 27 , wherein step (A) includes:
 providing synthetic reinforcement fibers, and   coating the fibers with a viscoelastic material.   
     
     
         34 . The method of  claim 27 , wherein step (A) includes:
 providing a web of viscoelastic material having a first glass transition temperature, and   impregnating the web with a viscoelastic material having a second glass transition temperature lower the first glass transition temperature.   
     
     
         35 . The method of  claim 27 , wherein step (A) includes introducing nano-particles into liquid viscoelastic material. 
     
     
         36 . The method of  claim 27 , wherein step (A) includes placing Z-fibers between the first and second layers to increase bending stiffness. 
     
     
         37 . The method of  claim 27 , wherein step (A) includes inserting Z-fibers into a film of viscoelastic film before step (A) is performed. 
     
     
         38 . A method of making a composite laminate structure, comprising the steps of:
 (A) forming first and second pre-pregs;   (B) forming a layer of damping material that provides the structure with damped qualities;   (C) introducing a reinforcement medium into the layer of damping material;   (D) forming a lay-up by placing the layer of reinforced damping material between the first and second pre-pregs; and,   (E) co-curing the lay-up.   
     
     
         39 . The method of  claim 38 , further comprising the step of:
 (E) compressing the first and second pre-pregs and the damping layer while step (E) is performed.   
     
     
         40 . The method of  claim 38 , wherein step (A) includes laying up multiples plies of a carbon fiber reinforced resin material. 
     
     
         41 . The method of  claim 38 , wherein steps (B) and (C) are performed by forming a pre-preg of thermoplastic coated reinforcing fibers. 
     
     
         42 . The method of  claim 41 , wherein the pre-preg of reinforcing fibers is formed by forming a web of the reinforcing fibers and passing the web through a bath of liquid thermoplastic material. 
     
     
         43 . The method of  claim 38 , wherein:
 step (C) includes providing a film containing a dispersion of reinforcing particles, and   step (B) includes bringing the film into face-to-face contact with the first pre-preg, and consolidating the film with the first pre-preg.   
     
     
         44 . The method of  claim 38 , wherein step (C) includes pressing a film of viscoelastic material onto a web of synthetic reinforcing fibers. 
     
     
         45 . The method of  claim 38 , wherein step (C) includes:
 providing synthetic reinforcement fibers, and   coating the fibers with a viscoelastic material.   
     
     
         46 . The method of  claim 38 , wherein step (C) includes:
 providing a web of viscoelastic material having a first glass transition temperature, and   impregnating the web with a viscoelastic material having a second glass transition temperature lower the first glass transition temperature.   
     
     
         47 . The method of  claim 38 , wherein step (C) includes bridging Z-fibers between the first and second pre-pregs.