Methods for fabricating composite structures with flanges having tethered corners

Abstract

Methods for fabricating a composite structure with a flange having a tethered corner involving providing a composite structure forming tool including a first endplate and a second endplate and having a composite structure formed thereabout, applying at least one ply of barrier fibers about the composite structure adjacent to the first endplate of the composite structure forming tool, and wrapping at least one fiber tow about the barrier fibers.

1 . A method for fabricating a composite structure with a flange having a tethered corner comprising:
 providing a composite structure forming tool including a first endplate and a second endplate and having a composite structure formed thereabout;   applying at least one ply of barrier fibers about the composite structure adjacent to the first endplate of the composite structure forming tool; and   wrapping at least one fiber tow about the barrier fibers.   
   
   
       2 . The method of  claim 1  wherein the barrier fibers are comprised of a material selected from the group consisting of glass fibers, graphite fibers, carbon fibers, ceramic fibers, aromatic polyamide fibers, and combinations thereof. 
   
   
       3 . The method of  claim 1  wherein the fiber tow is comprised of a material selected from the group consisting of glass fibers, graphite fibers, carbon fibers, ceramic fibers, aromatic polyamide fibers, and combinations thereof. 
   
   
       4 . The method of  claim 1  wherein the composite structure has a circumference and the barrier fibers are wrapped about the circumference of the composite structure adjacent to the first endplate of the composite structure forming tool to form a flange corner. 
   
   
       5 . The method of  claim 4  wherein the fiber tow is wrapped about the barrier fibers in the flange corner. 
   
   
       6 . The method of  claim 1  wherein the composite structure is a gas turbine engine fan casing. 
   
   
       7 . The method of  claim 1  wherein the flange is selected from the group consisting of end flanges, mounting flanges and combinations thereof. 
   
   
       8 . The method of  claim 1  wherein the barrier fibers comprise glass fibers. 
   
   
       9 . The method of  claim 1  wherein the fiber tow comprises carbon fiber. 
   
   
       10 . The method of  claim 1  wherein the fiber tow is wrapped about the barrier fibers from 3 to 6 times. 
   
   
       11 . The method of  claim 1  wherein more than one fiber tow is wrapped about the barrier fibers. 
   
   
       12 . A method for fabricating a composite structure with a flange having a tethered corner comprising:
 providing a composite structure forming tool including a first endplate and a second endplate and having a composite structure formed thereabout;   applying at least one ply of barrier fibers about the composite structure adjacent to the first endplate of the composite structure forming tool;   wrapping at least one fiber tow about the barrier fibers;   applying at least one ply of filler fibers over the fiber tow; and   applying at least one ply of flange fibers over the filler fibers to obtain a flange preform.   
   
   
       13 . The method of  claim 12  wherein the barrier fibers are comprised of a material selected from the group consisting of glass fibers, graphite fibers, carbon fibers, ceramic fibers, aromatic polyamide fibers, and combinations thereof. 
   
   
       14 . The method of  claim 12  wherein the fiber tow is comprised of a material selected from the group consisting of glass fibers, graphite fibers, carbon fibers, ceramic fibers, aromatic polyamide fibers, and combinations thereof. 
   
   
       15 . The method of  claim 12  wherein the composite structure has a circumference and the barrier fibers are wrapped about the circumference of the composite structure adjacent to the first endplate of the composite structure forming tool to form a flange corner. 
   
   
       16 . The method of  claim 15  wherein the fiber tow is wrapped about the barrier fibers in the flange corner. 
   
   
       17 . The method of  claim 12  wherein the composite structure is a gas turbine engine fan casing. 
   
   
       18 . The method of  claim 12  wherein more than one fiber tow is wrapped about the barrier fibers. 
   
   
       19 . The method of  claim 12  further comprising curing the flange preform to obtain a flange having a tethered corner. 
   
   
       20 . The method of  claim 12  wherein the flange is selected from the group consisting of end flanges, mounting flanges and combinations thereof.