ASTM D4896-01(2016)
(Guide)Standard Guide for Use of Adhesive-Bonded Single Lap-Joint Specimen Test Results
Standard Guide for Use of Adhesive-Bonded Single Lap-Joint Specimen Test Results
SIGNIFICANCE AND USE
4.1 Single-lap specimens are economical, practical, and easy to make. They are the most widely used specimens for development, evaluation, and comparative studies involving adhesives and bonded products, including manufacturing quality control.
4.2 Special specimens and test methods have been developed that yield accurate estimates of the true shear strength of adhesives. These methods eliminate or minimize many of the deficiencies of the thin-adherend single-lap specimens, but are more difficult to make and test. (See Test Methods D3983, D4027, D4562, and E229.)
4.3 The misuse of strength values obtained from such Test Methods or Practices as D906, D1002, D1144, D1151, D1183, D1780, D2294, D2295, D2339, D3163, D3164, D3165, D3434, D3528, D3632, and D5868, as allowable design-stress values for structural joints could lead to product failure, property damage, and human injury.
SCOPE
1.1 This guide is directed toward the safe and appropriate use of strength values obtained from test methods using single-lap adhesive joint specimens.
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.3 The discussion focuses on shear strength as measured with small thin-adherend, single-lap specimens. Many factors, however, apply to shear modulus, tensile strength, and tensile modulus measured by small laboratory specimens in general. This discussion is limited to single-lap specimens and shear strength only for simplification.
General Information
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Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D4896 − 01 (Reapproved 2016)
Standard Guide for
Use of Adhesive-Bonded Single Lap-Joint Specimen Test
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Results
This standard is issued under the fixed designation D4896; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
The true strength of an adhesive is a material property independent of the joint geometry, adherend
properties,andload,andisagoodstartingpointfordetermininganallowabledesignstress.Allowable
stresses in shear and tension are needed to design safe, efficient, adhesively bonded joints and
structures. The true shear strength, however, cannot be easily determined using single-lap specimens.
Many factors affect the apparent shear strength of an adhesive when measured with a small
laboratoryspecimen,andinparticular,withasingle-lapspecimen.Forexample,thefailureofatypical
single-lap specimen, is usually controlled by the tensile stress in the adhesive, and not by the shear
stress. The factors that control the tensile stress in lap-joint specimen, and thus, the apparent shear
strength are the size and shape of the specimen, the properties of the adherends, the presence of
internal stresses or flaws, and the changes that take place in the specimen due to adhesive cure and the
environment.Similarlythesefactorsaffecttheapparenttensilestrengthofanadhesiveinbutt-jointtest
specimens.
Due to the effects of these factors, the apparent shear strength obtained through measurements on
small laboratory specimens may vary widely from the true shear- or tensile-strength values needed to
determine allowable shear and tension design stresses.
Theobjectivesofthisguideare:todevelopanappreciationofthefactorsthatinfluencestrengthand
other stress measurements that are made with small laboratory test specimens; to foster the acceptable
uses of the widely used thin-adherend single-lap-joint test; and, specifically, to prevent misuse of the
test results.
1. Scope 2. Referenced Documents
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1.1 This guide is directed toward the safe and appropriate 2.1 ASTM Standards:
use of strength values obtained from test methods using D896 Practice for Resistance of Adhesive Bonds to Chemi-
single-lap adhesive joint specimens. cal Reagents
D906 Test Method for Strength Properties of Adhesives in
1.2 The values stated in inch-pound units are to be regarded
Plywood Type Construction in Shear by Tension Loading
as standard. The values given in parentheses are mathematical
D907 Terminology of Adhesives
conversions to SI units that are provided for information only
D1002 Test Method for Apparent Shear Strength of Single-
and are not considered standard.
Lap-Joint Adhesively Bonded Metal Specimens by Ten-
1.3 The discussion focuses on shear strength as measured
sion Loading (Metal-to-Metal)
with small thin-adherend, single-lap specimens. Many factors,
D1144 Practice for Determining Strength Development of
however, apply to shear modulus, tensile strength, and tensile
Adhesive Bonds
modulus measured by small laboratory specimens in general.
D1151 Practice for Effect of Moisture and Temperature on
This discussion is limited to single-lap specimens and shear
Adhesive Bonds
strength only for simplification.
D1183 Practices for Resistance of Adhesives to Cyclic
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ThisguideisunderthejurisdictionofASTMCommitteeD14onAdhesivesand
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is the direct responsibility of Subcommittee D14.80 on Metal Bonding Adhesives. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved May 1, 2016. Published May 2016. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
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approved in 1989. Last previous edition approved in 2008 as D4896 – 01 (2008) . Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/D4896-01R16. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D4896 − 01 (2016)
Laboratory Aging Conditions 3.4 strain—the unit change due to force, in the size or shape
D1780 Practice for Conducting Creep Tests of Metal-to- of a body referred to its original size or shape. Strain is a
Metal Adhesives nondimensional quantity, but is frequently expressed in inches
D2294 Test Method for Creep Properties of Adhesives in per inch, centimeters per centimeter, etc. (Refer to Terminol-
Shear by Tension Loading (Metal-to-Metal) ogy E6 for specific
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