1、Designation:D8285/D8285M19Standard Practice forCompressive Properties of Tapered and Stepped Joints ofPolymer Matrix Composite Laminates by SandwichConstruction Long Beam Flexure1This standard is issued under the fixed designation D8285/D8285M;the number immediately following the designation indicat
2、es theyear of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice covers the procedure for determination
3、 ofthe compressive strength of a tapered or stepped bonded jointof polymer matrix composite materials.It is applicable tosecondary bonded or co-bonded laminates with either unidi-rectional plies or woven fabric reinforcements.The materialsto be bonded may be different systems.In the bondline,asepara
4、te adhesive material may or may not be used(example:adhesives may be used with a prepreg system or may not beused with a wet lay-up repair system).The range of acceptabletest laminates and thicknesses are described in 8.2.7.Thestandard repair types are the same as for the tensile loading inPractice
5、D8131/D8131M.While external patch repairs are notexplicitly covered in this practice,these repairs could be testedas a non-standard specimen using this practice.1.2 This practice supplements Test Method D7249/D7249Mfor compressive loading of facesheet sandwich constructionsby long beam flexure.Sever
6、al important test specimen param-eters(for example,joint length,ply overlaps,step depth,andtaper ratio)are not mandated by this practice;however,theseparameters are required to be specified and reported to supportrepeatable results.1.3 Unidirectional(0 ply orientation)composites as well asmulti-dire
7、ctional composite laminates and fabric composites,can be tested.1.4 UnitsThe values stated in either SI units or inch-pound units are to be regarded separately as standard.Thevalues stated in each system are not necessarily exact equiva-lents;therefore,to ensure conformance with the standard,eachsys
8、tem shall be used independently of the other,and valuesfrom the two systems shall not be combined.1.4.1 Within the text,the inch-pound units are shown inbrackets.1.5 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user
9、 of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the
10、 Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D792 Test Methods for Density and Specific Gravity(Rela-tive Density)of Plastics
11、 by DisplacementD883 Terminology Relating to PlasticsD3171 Test Methods for Constituent Content of CompositeMaterialsD3878 Terminology for Composite MaterialsD5229/D5229M Test Method for MoistureAbsorption Prop-erties and Equilibrium Conditioning of Polymer MatrixComposite MaterialsD7249/D7249M Test
12、 Method for Facesheet Properties ofSandwich Constructions by Long Beam FlexureD8131/D8131M Practice for Tensile Properties of Taperedand Stepped Joints of Polymer Matrix Composite Lami-natesE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical Testin
13、gE122 Practice for Calculating Sample Size to Estimate,WithSpecified Precision,the Average for a Characteristic of aLot or ProcessE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE456 Terminology Relating to Quality and Statistics1This practice is under the jurisdiction of AS
14、TM Committee D30 on CompositeMaterials and is the direct responsibility of Subcommittee D30.09 on SandwichConstruction.Current edition approved Sept.1,2019.Published October 2019.DOI:10.1520/D8285_D8285M-19.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Se
15、rvice at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accord
16、ance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 E2533 Guide for Nondestructive Testing of Polymer MatrixComposites Used in Aerospace Applications2.2 SAE Document:3CMH-17 Composite Materials Handbook-17-Volume I3.Terminology3.1 DefinitionsTerminology D3878 defines terms relatingto hi
