ASTM D4027-98(2019)
(Test Method)Standard Test Method for Measuring Shear Properties of Structural Adhesives by the Modified-Rail Test
Standard Test Method for Measuring Shear Properties of Structural Adhesives by the Modified-Rail Test
SIGNIFICANCE AND USE
5.1 Structural design based on strength of materials principles or the theory of elasticity requires knowledge of the mechanical properties of the structural components, including adhesives. By the nature of their use, the most important adhesive properties are shear modulus and shear strength. A torsion test, such as described in Test Method E229, is theoretically the most accurate method for measuring adhesive shear properties. It is, however, impractical in many situations. For example, certain materials of construction are not readily adaptable to fabricating the thin-walled cylinders used as adherends in the torsion test. The modified-rail test does not have this disadvantage.
5.2 Two undesirable conditions occur in the modified-rail test specimens that do not occur in butt-joined cylinders; nonuniform shear-stress distribution along the joint, and the addition of some undefined combination of tension and compression stresses to the shear stress at a given location in the joint. The modified-rail shear tool minimizes but does not eliminate these undesirable effects.
5.3 Shear modulus, strength, and other properties are measured by the modified-rail method.
SCOPE
1.1 This test method describes equipment and procedures to measure the shear modulus and shear strength of adhesive layers between rigid adherends. The equipment may also be used for determining the adhesive’s shear creep compliance, the effects of strain history such as cyclic loading upon shear properties, and a failure criteria for biaxial stress conditions such as shear plus tension and shear plus compression.2
1.2 High-density wood shall be the preferred substrate. The practical upper limit on the shear modulus that can be measured is determined by the shear modulus of the adherends and by the strain measuring device. Thus, the practical limit of adhesive shear modulus that can be measured using high-density wood adherends is about 690 MPa (1 × 105 psi).
Note 1: Wood-base composites, metal, plastic, reinforced plastics, and other common construction materials may also be used for adherends.
1.3 The range of specimen dimensions that can be tested are: width 1.59 to 12.70 mm (0.0625 to 0.500 in.), length 102 to 203 mm (4 to 8 in.), and adherend thickness 13 to 25 mm (0.50 to 1.00 in.). The standard specimen dimensions shall be: width 3.18 mm (0.125 in.), length 203 mm (8 in.), and adherend thickness 19 mm (0.75 in.). Bondline thicknesses from 0.15 to 3.18 mm (0.006 to 0.125 in.) may be tested.
1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.6 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.
General Information
Relations
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:D4027 −98 (Reapproved 2019)
Standard Test Method for
Measuring Shear Properties of Structural Adhesives by the
Modified-Rail Test
This standard is issued under the fixed designation D4027; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 1.6 This international standard was developed in accor-
dance with internationally recognized principles on standard-
1.1 Thistestmethoddescribesequipmentandproceduresto
ization established in the Decision on Principles for the
measure the shear modulus and shear strength of adhesive
Development of International Standards, Guides and Recom-
layers between rigid adherends. The equipment may also be
mendations issued by the World Trade Organization Technical
used for determining the adhesive’s shear creep compliance,
Barriers to Trade (TBT) Committee.
the effects of strain history such as cyclic loading upon shear
properties, and a failure criteria for biaxial stress conditions
2. Referenced Documents
such as shear plus tension and shear plus compression.
2.1 ASTM Standards:
1.2 High-density wood shall be the preferred substrate. The
D905Test Method for Strength Properties of Adhesive
practical upper limit on the shear modulus that can be
Bonds in Shear by Compression Loading
measuredisdeterminedbytheshearmodulusoftheadherends
D907Terminology of Adhesives
and by the strain measuring device.Thus, the practical limit of
D4442Test Methods for Direct Moisture Content Measure-
adhesive shear modulus that can be measured using high-
ment of Wood and Wood-Based Materials
density wood adherends is about 690 MPa (1×10 psi).
E83Practice for Verification and Classification of Exten-
someter Systems
NOTE1—Wood-basecomposites,metal,plastic,reinforcedplastics,and
E229Test Method for Shear Strength and Shear Modulus of
other common construction materials may also be used for adherends.
Structural Adhesives (Withdrawn 2003)
1.3 The range of specimen dimensions that can be tested
are: width 1.59 to 12.70 mm (0.0625 to 0.500 in.), length 102
3. Terminology
to 203 mm (4 to 8 in.), and adherend thickness 13 to 25 mm
3.1 Definitions:
(0.50 to 1.00 in.). The standard specimen dimensions shall be:
3.1.1 Many terms in this test method are defined in Termi-
width 3.18 mm (0.125 in.), length 203 mm (8 in.), and
nology D907.
adherend thickness 19 mm (0.75 in.). Bondline thicknesses
3.1.2 shear modulus, n—the ratio of shear stress to corre-
from 0.15 to 3.18 mm (0.006 to 0.125 in.) may be tested.
sponding shear strain below the proportional limit. (Compare
1.4 The values stated in SI units are to be regarded as
secant modulus.)
standard. The values given in parentheses after SI units are
3.1.2.1 Discussion—The term shear modulus is generally
providedforinformationonlyandarenotconsideredstandard.
reserved for materials that exhibit linear elastic behavior over
most of their stress-strain diagram. Many adhesives exhibit
1.5 This standard does not purport to address all of the
curvilinear or nonelastic behavior, or both, in which case some
safety concerns, if any, associated with its use. It is the
other term, such as secant modulus, may be substituted.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
3.1.3 shear strain, n—thetangentoftheangularchange,due
mine the applicability of regulatory limitations prior to use.
to force between two lines originally perpendicular to each
other through a point in the body.
3.1.3.1 Discussion—Shear strain equals adherend slip/
1 adhesive layer thickness.
This test method is under the jurisdiction of ASTM Committee D14 on
Adhesives and is the direct responsibility of Subcommittee D14.70 on Construction
Adhesives.
Current edition approved March 1, 2019. Published March 2019. Originally For referenced ASTM standards, visit the ASTM website, www.astm.org, or
approved in 1981. Last previous edition approved in 2011 as D4027–98(2011). contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
DOI: 10.1520/D4027-98R19. Standards volume information, refer to the standard’s Document Summary page on
Kreuger, G. P., “Tests for the Shear Properties of Adhesives in Adherend- the ASTM website.
Adhesive Assemblies,” Unpublished report. Michigan Technological Institute, The last approved version of this historical standard is referenced on
Houghton, MI. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4027−98 (2019)
FIG. 1Top, Side, and End Views of the Modified-Rail Shear Apparatus
3.1.4 shear strength, n—in an adhesive joint, the maximum 3.2.6 shear stress, n—thestresscomponenttangentialtothe
average stress when a force is applied parallel to the joint. plane on which the forces act, that is, in the plane of the
3.1.4.1 Discussion—In most adhesive test methods, the bondline.
shearstrengthisactuallythemaximumaveragestressatfailure
3.2.7 slip, n—the relative collinear displacement of the
ofthespecimen,notnecessarilythetruemaximumstressinthe
adherends on either side of the adhesive layer in the direction
material.
of the applied load.
3.2.7.1 Discussion—This term differs from that of the
3.2 Definitions of Terms Specific to This Standard:
stress-strain diagram in that load and slip are not divided by
3.2.1 load, n—the force applied to the specimen at any
bond area and bond thickness (the constants that convert load
given time.
to stress and slip to strain). In actual practice, stress-strain
3.2.2 load-slip diagram, n—adiagraminwhichcorrespond-
information is generally collected in the form of a load-slip
ing values of load and slip are plotted against each other.
diagram for ease in plotting.
Values of load are usually plotted as ordinates and values of
3.2.8 stress–strain diagram, n—a diagram in which corre-
slip as abscissas.
sponding values of stress and strain are plotted against each
3.2.3 normal stress, n—the stress component perpendicular
other. Values of stress are usually plotted as ordinates (verti-
to a plane on which the forces act, that is, perpendicular to the
cally) and values of strain as abscissas (horizontally).
plane of the bondline.
4. Summary of Test Method
3.2.4 proportional limit, n—the maximum stress that a
material is capable of sustaining without significant deviation
4.1 Shear force is applied to the adhesive through the
from proportionality of stress to strain.
adherends by a modified-rail shear tool such as shown in Fig.
3.2.5 secant modulus, n—theslopeofthesecantdrawnfrom 1.Theadherendsarefirmlyclampedbetweentwopairsofrigid
the origin to any specified point on the stress-strain curve. rails as shown in Fig. 2. One pair is fixed and the other is
3.2.5.1 Discussion—Modulus is expressed in force per unit movable. The rigid rails limit undesired adherend deformation
area (megapascals, pounds-force per square inch, etc.). during testing. The pair of movable rails is fixed to two
D4027−98 (2019)
FIG. 2Top View of the Rail Clamps Showing How the Specimen Is Gripped for Testing
counter-moment pivot arms. These arms restrict the attached 5. Significance and Use
rails (and clamped adherend) to collinear motion with respect
5.1 Structural design based on strength of materials prin-
to the fixed rails (and clamped adherend). The results of using
ciples or the theory of elasticity requires knowledge of the
thissheartoolarenearlyuniformstressandstraindistributions
mechanical properties of the structural components, including
and the reduction of normal stress in the adhesive layer under
adhesives. By the nature of their use, the most important
load. Such conditions are necessary for accurate measurement
adhesive properties are shear modulus and shear strength. A
of the adhesive shear properties.
torsion test, such as described in Test Method E229,is
4.2 A known amount of uniform tensile or compression theoretically the most accurate method for measuring adhesive
force can be applied to the adhesive layer by the shear tool in shearproperties.Itis,however,impracticalinmanysituations.
order to develop a fracture criteria for the adhesive under For example, certain materials of construction are not readily
combined states of stress, such as shear plus tension, or shear adaptable to fabricating the thin-walled cylinders used as
plus compression, which commonly occur in bonded struc- adherends in the torsion test. The modified-rail test does not
tures. Fig. 3 shows combined shear and tensile forces on the have this disadvantage.
clamped specimen.
5.2 Two undesirable conditions occur in the modified-rail
4.3 The basic output of the test method is the bond shear test specimens that do not occur in butt-joined cylinders;
strength determined as the shear stress at failure, and the nonuniform shear-stress distribution along the joint, and the
stress-strain diagram determined from the plot of load on the addition of some undefined combination of tension and com-
shear tool versus the shear displacement of the bond line. pression stresses to the shear stress at a given location in the
joint. The modified-rail shear tool minimizes but does not
4.4 Bond strength and the stress-strain diagram may be
eliminate these undesirable effects.
obtainedforavarietyofenvironmentalandloadingconditions.
Specific recommendations are made for a minimum test 5.3 Shear modulus, strength, and other properties are mea-
program. sured by the modified-rail method.
D4027−98 (2019)
NOTE 1—During a shear only test the horizontal arrows (tension forces) would be absent.
FIG. 3Side View of the Rail Clamps Showing the Forces On the Clamps (Specimen) During Combined Shear and Tension Loading
6. Apparatus 6.2.1 Ashear tool suitable for this test method is illustrated
in Fig. 1, Fig. 2, Fig. 4, Fig. 5, and Fig. 6.
6.1 Universal Testing Machine:
6.2.2 The shear tool is fitted with a threaded bolt (Adjuster,
6.1.1 The universal testing machine shall have a minimum
Fig. 1 ) to apply normal force for combined stress studies.The
load capacity of 8900 N (2000 lbf), and a range of crosshead
magnitudeofthenormalforceisconstantfromtheoutsetofthe
speedfrom0.317to10.16mm/min(0.0125to0.40in./min).A
test.Thebolthasastraingagebondedtoitthat,withasuitable
minimum vertical space of 508 mm (20 in.) and horizontal
readout device and calibration, can be used to set the desired
space of 305 mm (12 in.) is required to install the shear tool in
normal force.
the testing machine.
6.1.2 The testing machine shall have a device capable of 6.3 Slip or Strain Gage—Since the shear strain of adhesive
readingtheloadtothenearest4.5 60.9N(1.0 60.2lbf).This layers will normally be very small, anASTM ClassAor Class
readout device should preferably be an electronic load cell to
facilitate simultaneous recording of load with the adhesive
Complete detail drawings of the modified-rail shear apparatus are available
deformation.
from the Forest Products Laboratory, Forest Service, U.S. Department of
6.2 Modified-Rail Shear Tool: Agriculture, Madison, WI 53705.
D4027−98 (2019)
FIG. 4Detail Drawings of Modified-Rail Shear Apparatus
FIG. 5Schematic Diagram Showing Use of the Modified-Rail Shear Apparatus With a Universal Test Machine to Apply Load
B-1extensometerasdescribedinPracticeE83shallbeused.A shear slip indirectly by attachment of the LVDT to the
mechanical-electrical transducer such as the linear variable specimen clamps. Or miniature electrical resistance strain
differential transducer (LVDT) can be used to measure the
D4027−98 (2019)
FIG. 6Schematic Diagram Showing Use of the Modified-Rail Shear Apparatus With an Integral Hydraulic Cylinder to Apply Load
gages can be used to measure the shear strain by direct 9. Test Specimen
attachment to the adhesive joint.
9.1 Specimen Dimensions:
9.1.1 The standard specimen dimensions are shown in Fig.
7. Materials
7. The thickness of the specimen may range from 1.59 to 12.7
7.1 The adhesives used shall be selected by the adhesive
mm (0.06 to 0.50 in.) at the discretion of the party requesting
manufacturer or by the party requesting these tests.
the tests.
7.2 Hard maple shall be the standard material for specimen
9.1.2 The recommended bondline thickness shall be 0.79
adherends. Other species may be selected at the option of the
mm (0.031 in.) with the following exceptions:
adhesive manufacturer or by the party requesting these tests.
9.1.2.1 Bondline thickness may be varied when this test
7.2.1 Generally a high-density wood such as hard maple,
method is used to measure the effects of bondline thickness
yellow birch, Douglas-fir, or southern pine are desirable to
upon strength and shear modulus.
minimize wood deformation effects on the measured adhesive
9.1.2.2 Bondline thickness shall never be greater than the
deformation. The specific gravity of the lumber selected shall
adhesive manufacturer’s stated maximum thickness.
equal or exceed average specific gravity for the species as
6 9.1.3 The maximum range of bondline thickness that is
given in Table4-2 of the Wood Handbook. For hard maple,
acceptableforuseinthistestmethodis0.15to3.18mm(0.006
the average is 0.63. A method of selecting maple lumber of
to 0.125 in.).
satisfactoryspecificgravityisdescribedintheappendixtoTest
Method D905.
9.2 Specimen Preparation:
7.2.2 A uniform textured wood such as maple or birch is
9.2.1 Cut the lumber into pieces measuring nominal 25 by
desirable to minimize wood density variation effects on the
64 by 305 mm (1 by 2.5 by 12 in.) with the grain in the long
adhesive layer. Coarse-textured woods such as Douglas-fir,
direction. Lightly surface both faces of each piece. Condition
hemlock, or southern pine are acceptable however.
these pieces to an equilibrium moisture content between 7 and
7.2.3 The wood shall be nominal 25.4 mm (1 in.) flat-sawn
10% (ovendry basis) or to the moisture content specified by
lumber presenting a flat grain (tangential surface) for bonding.
the adhesive manufacturer. Determine moisture content at
7.2.4 The lumber shall be straight-grained and free of
equilibrium from extra pieces of lumber in accordance with
defects including knots, cracks, abrupt grain deviations, decay,
Proced
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.