1、SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirelyvoluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefro
2、m, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions.Copyright 1999 Society of Automotive Engineers, Inc.All rights reserved. Printed in U.S.
3、A.QUESTIONS REGARDING THIS DOCUMENT: (724) 772-7121 FAX: (724) 776-0243TO PLACE A DOCUMENT ORDER: (724) 776-4970 FAX: (724) 776-0790SAE WEB ADDRESS: http:/www.sae.org400 Commonwealth Drive, Warrendale, PA 15096-0001AEROSPACE MATERIAL SPECIFICATIONAMS-STD-401Issued JUN 1999Sandwich Constructions and
4、Core Materials;General Test MethodsNOTICEThis document has been taken directly from U.S. Military Specification MIL-STD-401B and contains only minor editorial and format changes required to bring it into conformance with the publishing requirements of SAE technical standards. The initial release of
5、this document is intended to replace MIL-STD-401B. Any part numbers established by the original specification remain unchanged.The original Military Specification was adopted as an SAE standard under the provisions of the SAE Technical Standards Board (TSB) Rules and Regulations (TSB 001) pertaining
6、 to accelerated adoption of government specifications and standards. TSB rules provide for (a) the publication of portions of unrevised government specifications and standards without consensus voting at the SAE Committee level, and (b) the use of the existing government specification or standard fo
7、rmat.Under Department of Defense policies and procedures, any qualification requirements and associated qualified products lists are mandatory for DOD contracts. Any requirement relating to qualified products lists (QPLs) has not been adopted by SAE and is not part of this SAE technical document.AMS
8、-STD-401 SAE AMS-STD-401- 2 -CONTENTSPageParagraph 1. SCOPE 41.1 Scope 42. APPLICABLE DOCUMENTS 42.1 U.S. Government Publications 42.2 ASTM Publications 43. DEFINITIONS 53.1 General 53.1.1 Sandwich 53.1.2 Core 53.1.3 Facing 53.1.4 Flatwise 53.1.5 Edgewise 53.1.6 Isotropic 53.1.7 Orthotropic 53.1.7.1
9、 Orthotropic facing directions 53.1.7.2 Orthotropic core directions 64. GENERAL REQUIREMENTS 64.1 Selection of test samples 64.1.1 Design data 64.1.2 Quality assurance provisions 64.1.2.1 Sampling for the various inspections, examinations and tests 64.2 Test conditions 74.3 Test apparatus 74.4 Repor
10、t of test results 84.5 Designation of units of measurement 85. DETAIL TEST METHODS 85.1 Core Test Methods 85.1.1 Core Density and Specific Gravity 85.1.2 Core Moisture Sorption 95.1.3 Core Thermal Conductivity 105.1.4 Core Compression 105.1.5 Core Shear 125.1.6 Core Tension 155.1.7 Core Water Migrat
11、ion 155.1.8 Core Delamination of Honeycomb Core 165.2 Sandwich test methods 175.2.1 Sandwich Compression 175.2.2 Sandwich Shear 185.2.3 Sandwich Tension 185.2.4 Sandwich Flexure 195.2.5 Sandwich Thermal Conductivity 225.2.6 Sandwich Peel 235.3 Fatigue Tests 255.4 Creep Characteristics 26AMS-STD-401
12、SAE AMS-STD-401- 3 -FIGURESPageFigure 1. Axes notation for sandwich cores. 272. Sketch showing shear specimens attached to loadingplates and plane of action of applied loads. 283. Compression test apparatus showing an adjustable supportingbase and slotted round bars in position on the specimen ends.
13、Deformations are being measured with Martens mirrorcompressometers. 294. Test apparatus for tension flatwise test of core material forsandwich-type constructions showing specimens and fitting forapplying load. 305. Apparatus for conducting flexure test of sandwich construction. 316. Type of apparatu
14、s suitable for making sandwich peel test. 327. Possible modes of failure of sandwich composite under edgewiseloads: General buckling, shear crimping, dimpling of facings,and wrinkling of facings either away from or into the core 338. Apparatus for node strength tests. 34AMS-STD-401 SAE AMS-STD-401-
15、4 -1. SCOPE:1.1 Scope: This standard covers the general requirements and methods for testing sandwich core materials and for testing sandwich construction of the types used primarily in aircraft structures. This standard does not include test methods applicable only to a specific product; such test
16、methods are included in the detailed specifications for the product.2. APPLICABLE DOCUMENTS 1/: The following publications, of the issue in effect on date of invitation for bids or request for proposal, form a part of this specification to the extent specified herein.2.1 U.S. Government Publications
17、: Available from DODSSP, Subscription Services Desk, Building 4D, 700 Robbins Avenue, Philadelphia, PA 19111-5094.MIL-STD-105 Sampling Procedures and Tables for Inspection by Attributes2.2 ASTM Publications: Available from ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959.ASTM C 177 Meth
18、od of Test for Thermal Conductivity of Materials by Means of the Guarded Hot PlateASTM C 236 Method of Test for Thermal Conductance and Transmittance of Built-up Sections by Means of the Guarded Hot BoxASTM C 271 Method of Test for Density of Core Materials for Structural Sandwich ConstructionsASTM
19、C 272 Method of Test for Water Absorption of Core Materials for Structural Sandwich ConstructionsASTM C 273 Method of Shear Test in Flatwise Plane of Flat Sandwich Constructions or Sandwich CoresASTM C 297 Methods for Tension Test of Flat Sandwich Constructions in Flatwise Plane1/ Designations of co
20、mparable test methods of the American Society for Testing and Materials (ASTM) are given, where they exist, for reference information. The methods specified herein are similar in techniques and procedures to the ASTM methods but are frequently more restricted in scope to include tests specifically a
21、pplicable to sandwich constructions for aircraft.AMS-STD-401 SAE AMS-STD-401- 5 -2.2 (Continued):ASTM C 363 Method of Test for Delamination Strength of Honeycomb Type Core MaterialASTM C 364 Method of Test for Edgewise Compressive Strength of Flat Sandwich ConstructionsASTM C 365 Method of Test for
22、Flatwise Compressive Strength of Sandwich CoresASTM C 393 Method of Flexure Test of Flat Sandwich ConstructionsASTM C 394 Method of Test for Shear Fatigue of Sandwich Core MaterialsASTM D 1781 Method for Climbing Drum Peel Test for Adhesives3. DEFINITIONS: 3.1 General: The following terms are used t
23、hroughout this standard and their interpretation shall be construed in accordance with the following definitions.3.1.1 Sandwich: A laminar construction, consisting of thin facings bonded to a relatively thick lightweight core, resulting in a rigid and lightweight panel. In this standard, bonded mean
24、s “joined by welding, brazing or adhesive.”3.1.2 Core: A lightweight natural, synthetic, or fabricated material bonded between the facings of sandwich construction in order to separate the facings and to support them against buckling under stress.3.1.3 Facing: One of the two outer layers which have
25、been bonded to the core of a sandwich.3.1.4 Flatwise: Describes the application of forces in a direction normal to the plane of sandwich. Thus flatwise compression and flatwise tension designate forces applied to compress the sandwich core and to pull the facings from the core, respectively. Flatwis
26、e flexure designates bending so as to produce curvature of the plane of a sheet of sandwich.3.1.5 Edgewise: Describes the application of forces in directions parallel and actually in the plane of a sheet of sandwich.3.1.6 Isotropic: Describes material, either facings or cores, having the same proper
27、ties in all directions.3.1.7 Orthotropic: Describes material, either facings or cores, having different strength and elastic properties in different directions.3.1.7.1 Orthotropic facing directions are usually described in terms appropriate to the facing composition such as warp and fill direction i
28、n cloth, for example.AMS-STD-401 SAE AMS-STD-401- 6 -3.1.7.2 Orthotropic core directions for the identification of the different axes for strength determinations are designated as “T,” “L,” and “W,” which are specified for the following cores;These directions are further defined by the sketches of F
29、igure 1.4. GENERAL REQUIREMENTS: 4.1 Selection of test samples: The number of samples to be chosen and the method of their selection depend on the purpose of the particular tests under consideration.4.1.1 Design data: If tests are to be made to determine design values for cores, consideration must b
30、e given to the number of samples to be tested, and the number of specimens to be tested from each sample. It is suggested that at least 12 samples be tested to furnish average values and standard deviation to indicate variability and reliability of the data for selecting appropriate design values. T
31、he average values, number of tests, and standard deviation shall be reported.4.1.2 Quality assurance provisions: 4.1.2.1 Sampling for the various inspections, examinations and tests: Where the inspection lot consists of a number of supposedly identical items, the provisions of MIL-STD-105 apply and
32、should be referenced. The inspection level and Acceptable Quality Level (AQL) to be used will depend upon the expense and importance of the tests involved.If the inspection lot is of such a nature that MIL-STD-105 should not be used, then not less than five (5) specimens of a given type shall be tes
33、ted for lot acceptance, with a clear statement of what shall constitute acceptance or rejection of the lot.When appropriate, variables sampling plans may be used instead of attribute plans.AMS-STD-401 SAE AMS-STD-401- 7 -4.2 Test conditions: The conditions of test depend on the purpose of the partic
34、ular tests under consideration and should be stipulated in the procurement specification for the material. Normal or room temperature tests shall be conducted at 73 2 F (23 1 C) and 50 4 percent relative humidity. If the physical properties of the materials being tested are affected by moisture, the
35、 test specimens shall be brought to constant weight before testing, preferably in a conditioning chamber with temperature and humidity control. The tests shall preferably be made in a room under the same conditions. This would provide specimens having a uniform moisture content, and changes in moist
36、ure content would not occur during test.Care shall be taken in processing specimens which may have been exposed to high humidity and conditions other than normal. Specimens to which loading fittings are bonded should be conditioned prior to bonding the fittings otherwise conditioning may not penetra
37、te to the entire specimen. The fittings should then be bonded to the specimens under the exposure conditions so as to avoid changing the state of the specimen as would be done by bonding a wet specimen in a hot press, for example.In conducting tests at high or low temperatures the specimen should be
38、 maintained at the desired temperature until thermocouple readings taken within the specimen show constant temperature throughout the specimen. A check on one or two specimens will usually indicate how much time is needed for attaining equilibrium conditions.4.3 Test apparatus: Apparatus for perform
39、ing specific tests is described in the detailed test method and special apparatus for certain materials is described in procurement specifications for the material. General requirements presented here shall be met by apparatus for any tests. Measuring equipment for determining specimen dimensions an
40、d weights shall not be in error by more than 1/2 percent. The testing machine shall measure loads within 1 percent of the true load applied. Mass inertia effects of machine fixtures and specimens shall be properly accounted for in calibration of repeated loading test machines so that loading is corr
41、ect in the load range and machine speeds being used. The speed of the testing machine shall not deviate by more than 25 percent from the specified rate. Strain gages shall measure strains within 1 percent of their readings. Specific test methods may specify smaller allowable errors but the errors sp
42、ecified here shall not be exceeded in any test. Apparatus for tests, at elevated temperature, should be free of oils and grease and other surface contaminants that might solidify and interfere with free motion of movable parts, such as knife edges and bearings. Apparatus should be made of materials
43、that can withstand long exposure to the elevated temperature without serious deterioration. Stainless steel has been found satisfactory for temperatures up to 1600 F (870 C). Heating can be done in an oven at the milder temperatures, but it will be found advantageous to use radiant heat sources, suc
44、h as quartz lamps, at higher temperatures.AMS-STD-401 SAE AMS-STD-401- 8 -4.4 Report of test results: The report of each test shall include a complete description of the material tested. Cores shall be described in detail as to the type of material configuration, orientation, and density. Descriptio
45、ns of sandwich constructions shall include the type, size, and orientation of the facings, the procedure and materials used to bond the facings to the core, and detailed description of the core and its orientation.The report shall give information on the previous conditioning of test specimens and t
46、he conditions during testing.The report shall include a description of the testing machine and testing apparatus used to measure deformations or deflections.The report shall include a brief description of testing procedures and shall give detailed descriptions and discussions of procedures which dif
47、fer from those prescribed in this Standard.Test results shall be presented in concise form including tables of data, diagrams and graphs, where necessary, and descriptions of test failures, including photographs, if necessary.4.5 Designation of units of measurement: Dimensions, weights, forces, and
48、temperatures are given in U.S. Customary Units and in International Units SI. Values given in the Standard might not be converted literally, but are rounded for convenience and to correspond to accuracy of available measuring instruments.5. DETAIL TEST METHODS: 5.1 Core test methods: 5.1.1 Core Dens
49、ity and Specific Gravity (ASTM C 271): 5.1.1.1 Scope: The method describes a test procedure for determining the apparent density and specific gravity of cores of sandwich construction.5.1.1.2 Test specimens: The test specimens may be any convenient size or shape of core material that can be accurately measured. The number of test specimens shall be determined in accordance with 4.1. The test conditions shall conform to 4.2.5.1.1.3 Test procedure: The test specimens shall be weighed to an accuracy of 0.5 percent and the dimensions measured within an accuracy of 0.5 percent.AMS-S
