Component with internal damping

Abstract

A method of manufacturing a component such as a gas turbine fan blade. The method comprises: disposing a plurality of webs between a plurality of panels; and deforming the panels and the webs by applying internal pressure between the panels, thereby forming a series of internal cavities ( 15 ) partitioned by the webs ( 20 - 22 ). Weakened regions ( 30 a , 30 b , 30 c ) are formed in the webs which open to form holes ( 30 ) in the webs ( 20 - 22 ) during the deformation step. A damping material ( 17 ) is introduced into at least one of the cavities ( 15 ) whereby it flows from the cavity into the other cavities via the holes in the webs.

1 . A method of manufacturing a component, the method comprising: disposing a plurality of webs between a plurality of panels; and deforming the panels and the webs by applying internal pressure between the panels, thereby forming a series of internal cavities partitioned by the webs, characterised in that the method further comprises:
 forming weakened regions in the webs which open to form holes in the webs during the deformation step; and   introducing a damping material into at least one of the cavities whereby it flows into the other cavities via the holes in the webs.   
     
     
         2 . The method of  claim 1 , wherein the webs are deformed superplastically. 
     
     
         3 . The method of  claim 1 , wherein the webs comprise spaced-apart web regions of a membrane precursor, and the method further comprises bonding the membrane precursor between the web regions to an opposed pair of the panels. 
     
     
         4 . The method of  claim 3 , further comprising applying a stop-off material to prevent or minimise bonding between the web regions of the membrane precursor and the opposed pair of panels. 
     
     
         5 . The method of  claim 4 , wherein the stop-off material is applied to the opposed pair of panels. 
     
     
         6 . The method of  claim 4 , wherein the stop-off material is applied in a striped pattern, the spaces between adjacent stripes on one side of the membrane precursor being disposed opposite a stripe on the other side of the membrane precursor, whereby the webs forms a warren girder structure within the component. 
     
     
         7 . The method of any  claim 1 , wherein the component is a component for a gas turbine engine. 
     
     
         8 . The method of  claim 1  wherein the component rotates when in use, and the webs extend in a radial direction. 
     
     
         9 . The method of  claim 1  further comprising hardening the damping material after it has flowed into the cavities. 
     
     
         10 . The method of  claim 1  wherein the damping material is introduced into only one of the cavities, and flows from that cavity into all other cavities. 
     
     
         11 . The method of  claim 10  wherein the damping material is introduced into the one cavity via only one port. 
     
     
         12 . The method of  claim 1  wherein the weakened regions are formed by cutting the webs. 
     
     
         13 . The method of  claim 1  wherein the weakened regions are formed by removing material from the webs. 
     
     
         14 . The method of  claim 1  wherein the weakened regions are formed without removing material from the webs. 
     
     
         15 . A precursor assembly for forming a component, the assembly comprising: a plurality of panel precursors; and a membrane precursor disposed between the panel precursors, characterised in that the assembly further comprises a plurality of weakened regions formed in a plurality of spaced-apart web regions of the membrane precursor. 
     
     
         16 . The assembly of  claim 15  wherein the membrane precursor is bonded between the web regions to an opposed pair of the panel precursors. 
     
     
         17 . The assembly of  claim 16 , further comprising a stop-off material disposed between the web regions to prevent or minimise bonding between the membrane precursor and an opposed pair of the panels. 
     
     
         18 . The assembly of  claim 17 , wherein the stop-off material is applied in a striped pattern, the spaces between adjacent stripes on one side of the membrane precursor being disposed opposite a stripe on the other side of the membrane precursor. 
     
     
         19 . A component comprising:
 a plurality of panels; and   a plurality of webs extending between the panels and partitioning the component into a plurality of internal cavities,   characterised in that the component further comprises:   an array of holes formed in each web; and   a damping material substantially filling the internal cavities.