ASTM_C_274_-_07.pdf

Designation:C27407Standard Terminology ofStructural Sandwich Constructions1This standard is issued under the fixed designation C274;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This terminology covers terms necessary for a basicuniform understanding and usage of the language peculiar tostructural sandwich constructions.The simplest structuralsandwich is a three layered construction formed by bonding athin layer(facing)to each side of a thick layer(core).2.Terminologyco-curing,ncuring a composite laminate and simultaneouslybonding it to the sandwich core.co-fab,nfabrication process where close-outs and inserts arebonded into the panel the same time the facings are bondedto the core.core,na centrally located layer of a sandwich construction,usually low density,which separates and stabilizes thefacings and transmits shear between the facings and providesmost of the shear rigidity of the construction.doublers,nan extra piece of facing attached to strength orstiffen the panel or to distribute the load more widely to thecore.facing delamination,nwhere the facing becomes disbondedfrom the core.face dimpling,nbuckling of the compressive facing into theindividual cells of the honeycomb core due to compressiveloading or the prepreg facing sagging into the individualhoneycomb cells during cocure.face wrinkling,nbuckling of the compressive facing into oraway from the core.This progresses the width of the paneland causes failure.facing,nthe outermost layer or composite component of asandwich construction,generally thin and of high density,which resists most of the edgewise loads and flatwisebending moments:synonymous with face,skin andfacesheet.inserts,napparatus placed into the sandwich for attachingitems:synonymous with hard points.shear crimping,nbuckling of the compressive facing due tolow core shear modulus.Usually causes the core to fail inshear at the crimp.structural sandwich construction,na laminar constructioncomprising a combination or alternating dissimilar simple orcomposite materials assembled and intimately fixed in rela-tion to each other so as to use the properties of each to attainspecific structural advantages for the whole assembly.3.Keywords3.1 core;facing;loads;rigidity;sandwich;sandwich con-struction;stiffnessASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard.Users of this standard are expressly advised that determination of the validity of any such patent rights,and the riskof infringement of such rights,are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised,either reapproved or withdrawn.Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters.Your comments will receive careful consideration at a meeting of theresponsible technical committee,which you may attend.If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards,at the address shown below.This standard is copyrighted by ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.Individual reprints(single or multiple copies)of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585(phone),610-832-9555(fax),or serviceastm.org(e-mail);or through the ASTM website(www.astm.org).Permission rights to photocopy the standard may also be secured from the ASTM website(www.astm.org/COPYRIGHT/).1This test method is under the jurisdiction of ASTM Committee D30 onComposite Materials and is the direct responsibility of Subcommittee D30.09 onSandwich Construction.Current edition approved June 1,2007.Published July 2007.Originally approvedin 1951.Last previous edition approved in 1999 as C274 99.DOI:10.1520/C0274-07.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1