Method of Making Core-Stiffened Structure

Abstract

A method of making a core-stiffened structure includes the steps of providing a honeycomb core having an adhesive disposed on first and second surfaces thereof, providing a first skin and a second skin, and assembling the first skin, the second skin, and the honeycomb core to form the core-stiffened structure. The method further includes the steps of curing the core-stiffened structure and inhibiting at least one of the first skin and the second skin from protruding into at least one cell of the honeycomb core during the step of curing the core-stiffened structure.

1 . A method of making a core-stiffened structure, comprising:
 providing a honeycomb core having an adhesive disposed on first and second surfaces thereof;   providing a first skin and a second skin;   assembling the first skin, the second skin, and the honeycomb core to form the core-stiffened structure;   curing the core-stiffened structure; and   inhibiting the first skin and the second skin from protruding into at least one cell of the honeycomb core during the step of curing the core-stiffened structure, comprising:
 providing a first stabilization skin in a perforated or porous configuration; 
 placing the first stabilization skin between the first skin and the first surface of the honeycomb core prior to performing the step of curing the core-stiffened structure; 
 providing a second stabilization skin in a perforated or porous configuration; and 
 placing the second stabilization skin between the second skin and the second surface of the honeycomb core prior to performing the step of curing the core-stiffened structure; 
 wherein the second stabilization skin inhibits the second skin from protruding into the at least one cell of the honeycomb core; and 
 wherein the first stabilization skin inhibits the first skin from protruding into the at least one cell of the honeycomb core; 
   wherein the first stabilization skin is substantially fully cured as the core-stiffened structure is assembled; and   wherein the adhesive is reticulated and configured to allow migration of fluid through the first skin, the second skin, and the honeycomb core.   
     
     
         2 . The method according to  claim 1 , wherein the inhibiting at least one of the first skin and the second skin from protruding into the cells of the honeycomb core comprises:
 providing a first stabilization skin; and   placing the first stabilization skin between the first skin and the first surface of the honeycomb core prior to performing the step of curing the core-stiffened structure;   wherein the first stabilization skin inhibits the first skin from protruding into the at least one cell of the honeycomb core.   
     
     
         3 . The method according to  claim 2 , wherein the inhibiting at least one of the first skin and the second skin from protruding into the cells of the honeycomb core further comprises:
 providing a second stabilization skin; and   placing the second stabilization skin between the second skin and the second surface of the honeycomb core prior to performing the step of curing the core-stiffened structure;   wherein the second stabilization skin inhibits the second skin from protruding into the at least one cell of the honeycomb core.   
     
     
         4 . The method according to  claim 2 , wherein the providing the first stabilization skin comprises:
 providing the first stabilization skin in a perforated or porous configuration.   
     
     
         5 . The method according to  claim 2 , wherein the providing the first stabilization skin comprises:
 providing the first stabilization skin in a substantially solid form.   
     
     
         6 . The method according to  claim 2 , wherein the providing the first stabilization skin comprises:
 providing the first stabilization skin in a partially cured state.   
     
     
         7 . The method according to  claim 1 , wherein the inhibiting at least one of the first skin and the second skin from protruding into the at least one cell of the honeycomb core comprises:
 at least partially curing the at least one of the first skin and the second skin prior to performing the step of assembling the first skin, the second skin, and the honeycomb core to form the core-stiffened structure.   
     
     
         8 . The method according to  claim 7 , wherein the at least partially curing the at least one of the first skin and the second skin comprises:
 providing an insert having a geometry corresponding to the honeycomb core; providing a first release film;   disposing the first release film between the first skin and the insert; processing the first skin and the second skin; and   removing the insert and the first release film.   
     
     
         9 . A method of making a core-stiffened structure, comprising:
 applying a first skin to a caul and sealing thereto with a first bagging material; applying a second skin to a tool and sealing thereto with a second bagging material;   providing a honeycomb core between the first bagging material and the second bagging material;   providing compressive force to the honeycomb core between the caul and the tool while at least partially curing the first and second skin so that physical characteristics in the core are transposed into the first and second skins; and   applying adhesive to the honeycomb core and performing a second curing cycle to directly bond the first skin, second skin, and the honeycomb core together, as well is complete curing of the first and second skins.   
     
     
         10 . The method, according to  claim 9 , wherein the providing compressive force to the honeycomb core comprises:
 providing a vacuum enabled by a third bagging material encompassing the first skin, the caul, the honeycomb core, and the second skin. Specification   
     
     
         11 . A core-stiffened assembly, comprising:
 a honeycomb core having a first surface and a second surface and defining a plurality of cells;   a first skin disposed on the first surface of the honeycomb core, the first skin terminating at a peripheral edge of the honeycomb core; and   a second skin disposed on the second surface of the honeycomb core and extending outside of the peripheral edge of the honeycomb core;   wherein the first skin and the second are separated so that the honeycomb core is exposed.   
     
     
         12 . The core-stiffened assembly, according to  claim 11 , wherein:
 the first skin includes at least one step so that a thickness of the first skin decreases in the at least one step before terminating at the peripheral edge of the honeycomb core.   
     
     
         13 . The core-stiffened assembly according to  claim 11 , further comprising:
 a thermoplastic plug disposed in at least one of the plurality of cells for inhibiting the first skin and the second skin from protruding into the at least one of the plurality of cells during curing of the core-stiffened assembly.   
     
     
         14 . The core-stiffened assembly according to  claim 11 , further comprising:
 one of a magnetorheological fluid and a ferrofluid disposed in at least one of the plurality of cells for inhibiting the first skin and the second skin from protruding into the at least one of the plurality of cells during curing of the core-stiffened assembly.   
     
     
         15 . The core-stiffened assembly according to  claim 11 , further comprising:
 a first release film disposed between the first skin and the honeycomb core; and   a second release film disposed between the second skin and the honeycomb core and between the second skin and the first skin.   
     
     
         16 . The core-stiffened assembly according to  claim 11 , further comprising:
 the first skin terminating at a peripheral edge of the honeycomb core; and   the second skin extending outside of the peripheral edge of the honeycomb core;   wherein the first skin and the second skin are separated so that the honeycomb core is exposed.   
     
     
         17 . The core-stiffened assembly according to  claim 11 , further comprising:
 the first skin includes at least one step so that a thickness of the first skin decreases in the at least one step before terminating at the peripheral edge of the honeycomb core.