Composite fan inlet blade containment

Abstract

A ribbed composite shell includes an annular grid of relatively thick crack arresting ribs embedded in a relatively thin annular shell and relatively thin panels in thin annular shell between arresting ribs wherein each of panels are completely surrounded by a set of relatively thick adjoining ones of ribs. A shell forward flange may extend radially inwardly from thin annular shell. Arresting ribs may include radially stacked layers of strips between radially stacked annular layers of shell. Annular grid may include a rectangular grid pattern, a diamond grid pattern, or a hexagonal grid pattern. A nacelle inlet may have the ribbed composite shell within one or both of radially spaced apart composite inner and outer skins of an inner barrel. Nacelle inlet may be part of attached to a fan casing and axially disposed forward of fan blades circumscribed by the casing. The inlet may be on an engine nacelle.

What is claimed is: 
     
       1. A ribbed composite shell comprising:
 an annular grid of relatively thick crack arresting ribs embedded in a relatively thin annular shell, and 
 relatively thin panels in the thin annular shell between the arresting ribs, 
 wherein each of the relatively thin panels is completely surrounded by a set of relatively thick adjoining ribs of the relatively thick crack arresting ribs, and wherein the arresting ribs comprise radially stacked layers of strips between radially stacked annular layers corresponding to narrow composite plies interspersed between annular wide composite plies, and wherein the narrow composite plies interspersed between the annular wide composite plies form the arresting ribs and the panels between the arresting ribs. 
 
     
     
       2. The ribbed composite shell in accordance with  claim 1 , further comprising a shell forward flange extending radially inwardly from the thin annular shell. 
     
     
       3. The ribbed composite shell in accordance with  claim 2 , further comprising an axial flange extension extending axially from the shell forward flange. 
     
     
       4. The ribbed composite shell in accordance with  claim 1 , further comprising a shell forward flange extending radially inwardly from the thin annular shell and an axial flange extension extending axially from the shell forward flange. 
     
     
       5. The ribbed composite shell in accordance with  claim 1  further comprising:
 the annular grid circumscribed about an axial centerline axis; 
 each of the panels surrounded at least in part by adjoining first and second ribs; 
 the crack arresting ribs arranged in a grid pattern chosen from the following grid patterns; 
 a rectangular grid pattern including the adjoining first ribs running axially and the adjoining second ribs running circumferentially relative to the axial centerline axis; 
 a diamond grid pattern including the adjoining first ribs running axially and circumferentially clockwise and the adjoining second ribs running axially and circumferentially counter-clockwise relative to the axial centerline axis; and 
 a hexagonal grid pattern including the adjoining first ribs running axially, the adjoining second ribs running axially and circumferentially clockwise, and adjoining third ribs running axially and circumferentially counter-clockwise relative to the axial centerline axis. 
 
     
     
       6. The ribbed composite shell in accordance with  claim 5 , further comprising a shell forward flange extending radially inwardly from the thin annular shell. 
     
     
       7. The ribbed composite shell in accordance with  claim 6 , further comprising an axial flange extension extending axially from the shell forward flange. 
     
     
       8. The ribbed composite shell in accordance with  claim 5 , further comprising the arresting ribs including radially stacked layers of strips between radially stacked annular layers. 
     
     
       9. The ribbed composite shell in accordance with  claim 8 , further comprising a shell forward flange extending radially inwardly from the thin annular shell. 
     
     
       10. The ribbed composite shell in accordance with  claim 9 , further comprising an axial flange extension extending axially from the shell forward flange. 
     
     
       11. The ribbed composite shell in accordance with  claim 8 , further comprising the annular grid of crack arresting ribs disposed only in an axially extending portion of the ribbed composite shell. 
     
     
       12. The ribbed composite shell in accordance with  claim 11  further comprising the axially extending portion at or near an aft end of the ribbed composite shell. 
     
     
       13. A nacelle inlet comprising:
 a rounded annular nose lip section radially disposed between radially spaced apart annular inner and outer barrels, 
 the inner barrel including radially spaced apart composite inner and outer skins, at least one of the inner and outer skins having a ribbed composite shell including an annular grid of relatively thick crack arresting ribs embedded in a relatively thin annular shell, wherein the arresting ribs comprise radially stacked layers of strips between radially stacked annular layers corresponding to narrow composite plies interspersed between annular wide composite plies, and wherein the narrow composite plies interspersed between the annular wide composite plies form the arresting ribs and the panels between the arresting ribs, and 
 relatively thin panels in the thin annular shell between the arresting ribs, and each of the panels completely surrounded by a set of relatively thick adjoining ribs of the relatively thick crack arresting ribs. 
 
     
     
       14. The nacelle inlet in accordance with  claim 13 , further comprising the outer skin having the ribbed composite shell and a shell forward flange extending radially inwardly from the thin annular shell. 
     
     
       15. The nacelle inlet in accordance with  claim 14 , further comprising an axial flange extension extending axially from the shell forward flange. 
     
     
       16. The nacelle inlet in accordance with  claim 13 , further comprising the arresting ribs including radially stacked layers of strips between radially stacked annular layers. 
     
     
       17. The nacelle inlet in accordance with  claim 16 , further comprising the annular grid of crack arresting ribs disposed only in an axially extending portion at or near an aft end of the ribbed composite shell. 
     
     
       18. The nacelle inlet in accordance with  claim 13 , further comprising:
 the annular grid circumscribed about an axial centerline axis; 
 each of the panels surrounded at least in part by adjoining first and second ribs; 
 the crack arresting ribs arranged in a grid pattern chosen from the following grid patterns; 
 a rectangular grid pattern including the adjoining first ribs running axially and the adjoining second ribs running circumferentially relative to the axial centerline axis; 
 a diamond grid pattern including the adjoining first ribs running axially and circumferentially clockwise and the adjoining second ribs running axially and circumferentially counter-clockwise relative to the axial centerline axis; and 
 a hexagonal grid pattern including the adjoining first ribs running axially, the adjoining second ribs running axially and circumferentially clockwise, and adjoining third ribs running axially and circumferentially counter-clockwise relative to the axial centerline axis. 
 
     
     
       19. The nacelle inlet in accordance with  claim 18 , further comprising the arresting ribs including radially stacked layers of strips between radially stacked annular layers. 
     
     
       20. The nacelle inlet in accordance with  claim 19 , further comprising the annular grid of crack arresting ribs disposed only in an axially extending portion at or near an aft end of the ribbed composite shell. 
     
     
       21. The nacelle inlet in accordance with  claim 20 , further comprising a honeycomb core) sandwiched between the inner and outer skins. 
     
     
       22. An aircraft gas turbine engine assembly comprising:
 an aircraft gas turbine engine including a fan assembly including a plurality of radially outwardly extending fan blades rotatable about a longitudinally extending axial centerline axis, 
 the engine mounted within a nacelle connected to a fan casing of the engine, 
 the fan casing circumscribed about the fan blades, 
 a nacelle inlet including a rounded annular nose lip section radially disposed between radially spaced apart annular inner and outer barrels axially disposed forward of the fan casing and the fan blades, 
 the inner barrel including radially spaced apart composite inner and outer skins, 
 at least one of the inner and outer skins having a ribbed composite shell including an annular grid of relatively thick crack arresting ribs embedded in a relatively thin annular shell, wherein the arresting ribs comprise radially stacked layers of strips between radially stacked annular layers corresponding to narrow composite plies interspersed between annular wide composite plies, 
 relatively thin panels in the thin annular shell between the arresting ribs, and 
 each of the panels completely surrounded by a set of relatively thick adjoining ribs of the relatively thick crack arresting ribs, wherein the narrow composite plies interspersed between the annular wide composite plies form the arresting ribs and the panels between the arresting ribs. 
 
     
     
       23. The aircraft gas turbine engine assembly in accordance with  claim 22 , further comprising the outer skin having the ribbed composite shell and a shell forward flange extending radially inwardly from the thin annular shell. 
     
     
       24. The aircraft gas turbine engine assembly in accordance with  claim 22 , further comprising the arresting ribs including radially stacked layers of strips between radially stacked annular layers. 
     
     
       25. The aircraft gas turbine engine assembly in accordance with  claim 24 , further comprising the annular grid of crack arresting ribs disposed only in an axially extending portion at or near an aft end of the ribbed composite shell. 
     
     
       26. The aircraft gas turbine engine assembly in accordance with  claim 22 , further comprising:
 the annular grid circumscribed about an axial centerline axis; 
 each of the panels surrounded at least in part by adjoining first and second ribs; 
 the crack arresting ribs arranged in a grid pattern chosen from the following grid patterns; 
 a rectangular grid pattern including the adjoining first ribs running axially and the adjoining second ribs running circumferentially relative to the axial centerline axis; 
 a diamond grid pattern including the adjoining first ribs running axially and circumferentially clockwise and the adjoining second ribs running axially and circumferentially counter-clockwise relative to the axial centerline axis ; and 
 a hexagonal grid pattern including the adjoining first ribs running axially, the adjoining second ribs running axially and circumferentially clockwise, and adjoining third ribs running axially and circumferentially counter-clockwise relative to the axial centerline axis. 
 
     
     
       27. The aircraft gas turbine engine assembly in accordance with  claim 26 , further comprising the arresting ribs including radially stacked layers of strips between radially stacked annular layers. 
     
     
       28. The aircraft gas turbine engine assembly in accordance with  claim 27 , further comprising the annular grid of crack arresting ribs disposed only in an axially extending portion at or near an aft end of the ribbed composite shell. 
     
     
       29. The aircraft gas turbine engine assembly in accordance with  claim 28 , further comprising a honeycomb core sandwiched between the inner and outer skins.