Impactor containment

Abstract

An impactor containment system including a laminate material, the laminate material having a face sheet, a cellular filling providing a crushable layer one side of which layer is arranged on the face sheet, and a stiff backing layer arranged on other side of the crushable layer, wherein the face sheet is provided with zones of weakness.

1 . An impactor containment system including a laminate material, the laminate material comprising:
 a face sheet, and   a cellular filling providing a crushable layer one side of which layer is arranged on the face sheet, and a stiff backing layer arranged on other side of the crushable layer, wherein the face sheet is provided with zones of weakness.   
     
     
         2 . An impactor containment system as claimed in  claim 1 , the laminate material further comprising a layer structure, arranged on the side of the face sheet away from the crushable layer, the layer structure having a further cellular filling providing a further crushable layer proximate the face sheet, and, arranged on the further crushable layer away from the face sheet, a further face sheet also provided with zones of weakness. 
     
     
         3 . An impactor containment system as claimed in  claim 2 , further comprising one or more further such layer structures in stacked arrangement. 
     
     
         4 . An impactor containment system as claimed in  claim 1 , wherein zones of weakness provided in the or a face sheet are provided by perforations in the face sheet concerned. 
     
     
         5 . An impactor containment system as claimed in  claim 1 , wherein zones of weakness provided in the or a face sheet are constituted by cuts in the face sheet concerned. 
     
     
         6 . An impactor containment system as claimed in  claim 5 , wherein the cuts in the face sheet concerned follow differently directed straight lines and/or follow curves such as ovals or geodesic curves. 
     
     
         7 . An impactor containment system as claimed in  claim 1 , wherein zones of weakness provided in the or a face sheet are constituted by dimpling in the face sheet concerned. 
     
     
         8 . An impactor containment system as claimed in  claim 7 , wherein the dimpling provides folds or creases or other discontinuities in the face sheet concerned. 
     
     
         9 . An impactor containment system as claimed in  claim 1 , wherein zones of weakness provided in the or a face sheet are constituted by tiling of the face sheet concerned. 
     
     
         10 . A gas turbine engine comprising:
 a casing,   an air intake,   a propulsive fan,   a pressure compressor,   a combustor,   a turbine arrangement,   an exhaust nozzle, and   an impactor containment system including a laminate material, the laminate material having:
 a face sheet, and 
 a cellular filling providing a crushable layer one side of which layer is arranged on the face sheet, and a stiff backing layer arranged on other side of the crushable layer, wherein the face sheet is provided with zones of weakness. 
   
     
     
         11 . A gas turbine engine as claimed in  claim 10 , wherein at least in the case of the outer face sheet of the laminate material some zones of weakness are directed along lines across the line of expected ice impact and some line up with the expected angle of blade impact in the event of blade break off.