EN ISO 18592:2009

SLOVENSKI STANDARD
01-april-2010
8SRURYQRYDUMHQMH3RUXãLWYHQRSUHVNXãDQMH]YDUQLKVSRMHY0HWRGDSUHVNXãDQMD
WUGQRVWLYHþWRþNRYQRYDUMHQLKY]RUFHY,62
Resistance welding - Destructive testing of welds - Method for the fatigue testing of multi-
spot-welded specimens (ISO 18592:2009)
Widerstandsschweißen - Zerstörende Prüfung von Schweißverbindungen - Verfahren zur
Schwingfestigkeitsprüfung von geschweißten Mehrpunktproben (ISO 18592:2009)
Soudage par résistance - Essais destructifs des soudures - Méthode d'essai de fatigue
des échantillons soudés par points multiples (ISO 18592:2009)
Ta slovenski standard je istoveten z: EN ISO 18592:2009
ICS:
25.160.40 Varjeni spoji in vari Welded joints
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 18592
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2009
ICS 25.160.40
English Version
Resistance welding - Destructive testing of welds - Method for
the fatigue testing of multi-spot-welded specimens (ISO
18592:2009)
Soudage par résistance - Essais destructifs des soudures - Widerstandsschweißen - Zerstörende Prüfung von
Méthode d'essai de fatigue des échantillons soudés par Schweißverbindungen - Verfahren zur
points multiples (ISO 18592:2009) Schwingfestigkeitsprüfung von geschweißten
Mehrpunktproben (ISO 18592:2009)
This European Standard was approved by CEN on 18 November 2009.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2009 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 18592:2009: E
worldwide for CEN national Members.

Contents Page
Foreword .3

Foreword
This document (EN ISO 18592:2009) has been prepared by Technical Committee ISO/TC 44 "Welding and
allied processes" in collaboration with Technical Committee CEN/TC 121 “Welding”, the secretariat of which is
held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by June 2010, and conflicting national standards shall be withdrawn at
the latest by June 2010.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of ISO 18592:2009 has been approved by CEN as a EN ISO 18592:2009 without any modification.

INTERNATIONAL ISO
STANDARD 18592
First edition
2009-12-15
Resistance welding — Destructive testing
of welds — Method for the fatigue testing
of multi-spot-welded specimens
Soudage par résistance — Essais destructifs des soudures — Méthode
d'essai de fatigue des échantillons soudés par points multiples

Reference number
ISO 18592:2009(E)
©
ISO 2009
ISO 18592:2009(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.

©  ISO 2009
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2009 – All rights reserved

ISO 18592:2009(E)
Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Normative references.2
3 Terms and definitions .3
4 Symbols and abbreviated terms .5
5 Specimens.7
5.1 General .7
5.2 Selection of suitable specimens.8
5.3 Specimen fabrication .10
5.4 Specimen geometry .11
6 Requirements for testing machine .21
7 Specimen grips and alignment .22
7.1 General .22
7.2 Shear and peel loading .23
8 Test procedure.24
8.1 General .24
8.2 Mounting the H-specimens.24
8.3 Clamping procedure for the H-specimens.24
8.4 Fatigue test .24
8.5 Test termination.25
9 Test report.27
9.1 Basic information .27
9.2 Presentation of fatigue test results .28
Annex A (informative) Calibration specimen for verifying the load distribution in H-specimens.30
Annex B (informative) Hydraulic grips for the fatigue testing of H-specimens.31
Annex C (informative) Grip for the fatigue testing of H-specimens.32
Annex D (informative) Flow chart — Data acquisition .33
Bibliography.36

ISO 18592:2009(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 18592 was prepared by Technical Committee ISO/TC 44, Welding and allied processes, Subcommittee
SC 6, Resistance welding and allied mechanical joining.
Requests for official interpretations of any aspect of this International Standard should be directed to the
Secretariat of ISO/TC 44/SC 6 via your national standards body. A complete listing of these bodies can be
found at www.iso.org.
iv © ISO 2009 – All rights reserved

ISO 18592:2009(E)
Introduction
This International Standard has been prepared because welding engineers (and most design engineers) are
not familiar with fatigue testing and the influence of factors such as load type (e.g. shear load, peel load), and
failure criteria.
Tests are used to investigate the existence of specific properties and their qualitative and quantitative
evaluation. Fatigue tests, in general, are used to investigate the behaviour of structures and components
subjected to cyclic loads. For welded components, fatigue tests are used to determine the influence of
different parameters such as joining methods, pitch, material thickness and material combinations type of load
(e.g. shear load, peel load), overlap, location of weld on flange, edge distance, loading condition (e.g. quasi-
static, cyclic, load ratio R), and the combination of environment and corrosion on the fatigue behaviour (life) of
spot welds and/or specimens subjected to various types of loads. Fatigue tests should, if their results are to be
used for design purposes, as far as possible, take into consideration such boundary conditions as
encountered in a real life environment. This applies to load types, load amplitudes, and load ratios as well as
load distributions and failure criteria (Reference [7]).
The test specimen selected for the fatigue test should simulate, as closely as possible, the loads and the
boundary conditions as they are encountered in service. Furthermore, the failure criterion used should
conform to the application in hand. Although the type of primary load is identical in some specimens, e.g.
shear load in flat multi-spot specimens, shear H-specimens, KS-2 specimens, and double disc specimens, the
results of fatigue tests differ significantly because of the secondary load types resulting from varying degrees
of local deformation due to the differences in the local stiffness in the area of the joints. The local deformation,
responsible for the magnitude of the peel component, for example, is a function of the local stiffness,
increasing with a decrease in stiffness.
This International Standard offers a framework within which the different specimens, described herein, can be
modified such that design specifics and production constraints, e.g. flange width and overlap, weld nugget
size, pitch, bending radius, and sub-standard welds, can be given due consideration. This helps towards
enhancing the significance of the results very appreciably.
Note that if welds could be subjected to identical amplitudes of shear and peel loads, their lives would differ by
a factor of approximately 10 (References [8] to [11]). This explains the necessity to use different specimens
for the simulation of different load types.
Conformance tests on real components serve the verification of design calculations and are necessary for the
qualification of structures. It is therefore necessary to maintain their number at an absolute minimum.

INTERNATIONAL STANDARD ISO 18592:2009(E)

Resistance welding — Destructive testing of welds — Method
for the fatigue testing of multi-spot-welded specimens
1 Scope
This International Standard specifies test specimens and procedures for performing constant load amplitude
fatigue tests on multi-spot-welded and multi-axial specimens in the thickness range from 0,5 mm to 5 mm at
room temperature and a relative humidity of max. 80 %. The applicability of this International Standard to
larger thicknesses can be limited by mechanical properties such as yield strength and formability of the
specimen material. The thickness range for advanced high strength steels (AHSS) is generally below 3,0 mm.
Greater thicknesses apply for aluminium alloys, for example.
Depending on the specimen used, it is possible from the results to evaluate the fatigue behaviour of:
a) spot welds subjected to defined uniform load distribution;
b) spot welds subjected to defined non-uniform load distribution;
c) spot welds subjected to different defined combinations of shear-, peel-and normal-tension loads; and
d) the tested specimen.
Multi-spot specimens with which the different load distributions can be realized are:
1) defined uniform load distribution:
i) H-specimens for shear- and peel-loading, (welds subjected to uniform shear or peel loading
transverse to the joint line),
ii) single- and double-hat specimens subjected to four-point bending (spot welds subjected to
uniform shear load in the direction of the row of welds),
iii) double-disc specimen under torsion (spot welds subjected to uniform shear load),
iv) double-disc specimen under tensile load (spot welds subjected to uniform peel load),
v) double-disc specimen under combined torsion and tensile loading,
vi) flat multi-spot specimens using defined grips;
2) defined non-uniform load distribution:
i) H-specimens with modified grips,
ii) modified H-specimens with standard grips,
iii) modified H-specimens with modified grips,
ISO 18592:2009(E)
iv) flat multi-spot specimens with modified grips,
v) modified multi-spot flat specimens with standard grips,
vi) modified multi-spot flat specimens with modified grips;
3) defined combinations of shear-, peel- and normal-tension loads:
i) the KS-2 specimen,
ii) the double disc specimen;
4) spot welds subjected to undefined non-uniform load distribution — single-hat, double-hat and similar
closed hollow sections under torsion, 3-point bending and/or internal pressure.
The specimens and tests referred to under 4) are not dealt with further in this International Standard, because
the results obtained with these specimens are specific to the components as tested and may not be
generalized or used for deriving data pertaining to the load-carrying behaviour of the welds. Results obtained
with such tests are suitable for comparing the mechanical properties of the tested components with those of
similar components tested in the same manner. These tests are, however, not suitable for evaluating or
comparing the load-carrying properties of the welds.
The test results of the fatigue tests obtained with component like specimens are suitable for deriving criteria
for the selection of materials and thickness combinations for structures and components subjected to cyclic
loading. This statement is especially relevant for results obtained with specimens with boundary conditions, i.e.
a local stiffness similar to that of the structure in question. The results of a fatigue test are suitable for direct
application to design only when the loading conditions in service and the stiffness of the design in the joint
area are identical.
NOTE Specimens are modified to take into consideration constraints or specific demands posed by design, e.g.
smaller than standard overlap, smaller or larger than standard nugget diameter, and specific load distribution, thus
enhancing the value of the test results for the design engineer.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 14273, Specimen dimensions and procedure for shear testing resistance spot, seam and embossed
projection welds
ISO 14324, Resistance spot welding — Destructive tests of welds — Method for the fatigue testing of spot
welded joints
ISO 15609-5:2004, Specification and qualification of welding procedures for metallic materials — Welding
procedure specification — Part 5: Resistance welding
2 © ISO 2009 – All rights reserved

ISO 18592:2009(E)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 14324 and the following apply.
3.1
repeated load
F
load varying simply and periodically between constant maximum and minimum values
NOTE Adapted from ISO 14324:2003, 3.12.
3.2
maximum load
F
max
highest algebraic value of the repeated load
NOTE Adapted from ISO 14324:2003, 3.9.
3.3
minimum load
F
min
lowest algebraic value of the repeated load
NOTE Adapted from ISO 14324:2003, 3.11.
3.4
load range
∆F
difference between maximum and minimum loads
∆F = F − F
max min
NOTE Adapted from ISO 14324:2003, 3.8.
3.5
load amplitude
F
a
half of the load range
F = 0,5∆F
a
NOTE Adapted from ISO 14324:2003, 3.6.
3.6
mean load
F
m
average of maximum and minimum loads
F = 0,5(F + F )
m max min
NOTE Adapted from ISO 14324:2003, 3.10.
3.7
load ratio
R
minimum load divided by the maximum load
F
min
R =
F
max
NOTE Adapted from ISO 14324:2003, 3.7.
ISO 18592:2009(E)
3.8
fatigue life
number of cycles to failure
N
f
number of cycles which can be applied at a specified repeated load before failure occurs
NOTE Adapted from ISO 14324:2003, 3.3.
3.9
fatigue endurance
N
number of cycles at which it has been agreed to stop the test even if failure does not occur
3.10
F-N curve
curve obtained by plotting the load amplitude (or load range, or maximum load) as ordinate and the fatigue life
(or fatigue endurance if the test is terminated before failure) as abscissa, also called the load-amplitude-
number of load cycles curve.
NOTE 1 It is normal practice to use logarithmic axes.
NOTE 2 Adapted from ISO 14324:2003, 3.5.
3.11
S-N curve
curve drawn by plotting the stress amplitude (or stress range, or maximum stress) as ordinate and the fatigue
life (or fatigue endurance if the test is terminated before failure) as abscissa, also called the stress-amplitude-
number of load cycles curve.
NOTE The S-N curve is generally not suitable for spot welded specimens.
3.12
endurance limit
maximum load amplitude F at which a test specimen can endure a specified number of load cycles without
max
failing
NOTE Adapted from ISO 14324:2003, 3.2.
3.13
fatigue limit at probability p
maximum load (range, amplitude or maximum value) at which the test specimen can endure an infinite
number of load cycles with the probability p
NOTE Usually, the probability selected is 50 %.
3.14
endurance limit at probability p
load (range, amplitude or maximum value) at which the test specimen can endure a specified number of load
cycles with the p probability without failing
NOTE The probability usually selected is 50 %.
3.15
displacement
∆L
change in the length of a specimen due to the application of a load
4 © ISO 2009 – All rights reserved

ISO 18592:2009(E)
3.16
stiffness
c
load F divided by the corresponding displacement L, i.e.
FF−
max min
c =
∆L
3.17
initial stiffness
c
stiffness at start of the test, i.e.
FF−
max min
c =
∆L
4 Symbols and abbreviated terms
a overlap
b test coupon width
b internal width of test coupon
i
b width of side plate
s
c stiffness
c initial stiffness
d diameter of central hole
c
d diameter of pitch circle
e
e pitch
F load, repeated load
F load amplitude
a
F mean load
m
F maximum load
max
F minimum load
min
F peel load
p
F maximum peel load
p,max
F minimum peel load
p,min
F peel load transverse to the joint line
pt
F shear load
s
F maximum shear load
s,max
F minimum shear load
s,min
F shear load parallel to or in the axis of the joint line
sp
F shear load transverse to the joint line
st
g bar distance
h outer height of hat-section
h coupon height
i
ISO 18592:2009(E)
h outer height
o
h total height of H-specimen
H
h height of side plate or side member
s
h height of L member
L
h height of U member
U
l distance between grip and overlap
a
l length of clamped area
c
l edge distance
e
l specimen length between clamps
f
l specimen length between grips
g
l total length of specimen
S
l length of test coupon
t
l distance from wall
w
L displacement
L maximum displacement
max
L minimum displacement
min
N number of load cycles
p probability
r bend radius for sheet thickness t
1 1
r bend radius for sheet thickness t
2 2
R load ratio
t time
t ; t sheet thicknesses
1 2
σ peel stress
p
σ peel stress transverse to the joint line
pt
σ shear stress
s
σ shear stress parallel to or in the axis of the joint line
sp
σ shear stress transverse to the joint line
st
∆L displacement (L − L )
max min
6 © ISO 2009 – All rights reserved

ISO 18592:2009(E)
5 Specimens
5.1 General
The specimens are designed to simulate, for joints in thin-walled structures, three basic types of loadings in
their primary forms, i.e. shear load transverse to the joint line, shear load parallel to or in the axis of the joint
line, and peel load (see Figure 1).

a)  Shear load transverse to the joint line and b)  Peel or one-sided cross-tension load
shear load in the axis of the joint line
NOTE See Clause 4.
Figure 1 — The three basic load cases for joints (Reference [9])
NOTE 1 For true-to-life thin-walled structures, it can generally be assumed that joints are never subjected to any of the
types of stresses listed in the first paragraph either singly or in a pure form. For lap joints, at least one type of shear stress
and, due to the local deformation of the sheets caused by it, peel stress are present. Even if the primary stress in a lap
joint is pure shear, a peel stress component is generated, whose absolute value depends on the magnitude of the
deformation caused by the shear stress in the joint. This deformation is a function of the bending moment, which depends
on the sheet thicknesses involved, the magnitudes of the forces acting and the local stiffness. The stiffness itself is a
function of the sheet thicknesses, the Young modulus of the material(s), the flange width, the overlap, the location of the
joint on the flange, the bending radii, etc. (References [8] to [11]).
NOTE 2 The specimens have been designed to permit the use of different joining methods, e.g. spot welding, self-
piercing riveting, clinching, friction stir spot welding, laser welding and GMA welding, and thus allow a comparison of the
load-carrying properties of joints made with different methods.
NOTE 3 For single- and double-hat specimens subjected to torsion and 3-point bending loads, the joints themselves
are subjected to complex loads, whereby the ratios of the load types and the load distribution are non-uniform and
undefined. Furthermore, the ratios of the three basic types of loads listed in the first paragraph of this subclause are a
function of the load amplitude, the clamping conditions, and the sheet material- and thickness combinations.
The quality, value and usefulness of the results of fatigue tests depend to a large extent on the degree of care
taken in the fabrication of the specimens, their testing, the acquisition and evaluation of test data, and the
comprehensiveness of the documentation.
ISO 18592:2009(E)
The documentation should contain the following information.
a) Material(s)
⎯ Material specification, type and thickness of coating(s), sheet thickness, surface condition and
mechanical properties should be noted.
b) Coupons
⎯ The coupons should, if possible, be taken from the same material lot.
⎯ The rolling direction shall be identical for all coupons and documented.
⎯ The required tolerances shall be adhered to.
⎯ Unintentional deformation of the coupons and damage to the surfaces is to be avoided.
c) Welding
⎯ Suitable jigs should be used to ensure accurate alignment of the coupons and location of the welds.
⎯ The welding parameters and the equipment used shall be documented.
d) Documentation
⎯ The relevant standards shall be referenced.
⎯ Any deviation from the referenced standards shall be documented.
The specimens shall be modified for the different joining methods, such that the joints are able to perform
under optimum boundary conditions, e.g. the flange width for laser welds can be reduced considerably as
compared to the length required for resistance spot welds. Similarly, because of the smaller space
requirements, the location of rectangular clinch joints on the flange can be much closer to the radius than is
the case with resistance spot welds unless eccentric welding electrodes are being used.
5.2 Selection of suitable specimens
The selection of a suitable specimen for the fatigue tests depends on the planned usage of the test results. A
basic requirement of the specimen is that it should allow the relevant load type and load ratio to be simulated.
If the results are to be used for design purposes, then it is important to employ specimens with which a similar
type of load distribution can be realized. Further, the stiffness of the specimen in the joint area should be
similar to that of the component under consideration.
Besides considering the primary loading condition of the welds, bear in mind the local stiffness of the joint
area in the component in question. The fatigue life of welds is influenced decisively by the peel load and not
by the shear load. For example, if welds could be subjected to identical amplitudes of shear and peel loads,
their lives would differ by a factor of ~10 . However, as can be seen in Figure 2, spot welds under shear load
would never fail under a load at which identical welds have a life of about 1 000 cycles. As stated above, the
magnitude of the peel component depends on the shear load and the local stiffness of the specimen.
Especially in the case of the single spot specimen, Figure 4, the local stiffness is much lower than is usual in
real structures. Therefore the peel/shear ratio is comparatively large, resulting in a significantly shorter fatigue
life as compared to identical welds tested on H-specimens, for example. In addition, some materials are
particularly sensitive to peel stress in the as-welded condition, so that results obtained with specimens with a
low stiffness can be misleading with regard to the behaviour of such welds in structures.
The H-specimens allow the investigation of almost all parameters including different stress ratios and stress
distributions. They require special grips for testing and their manufacture is relatively complicated. However,
8 © ISO 2009 – All rights reserved

ISO 18592:2009(E)
under uniform loading, it is possible with these specimens to obtain results with a high significance with 5 to
7 specimens.
When selecting a specimen some of the main considerations should be:
⎯ the simulation of the type of loading and load ratio in the component under consideration;
⎯ simulation of design parameters such as stiffness, pitch, edge and flange distance;
⎯ simulation of the stress distribution in the component;
⎯ effort required for manufacturing and testing;
⎯ number of specimens required to obtain statistically significant results.
Note that results obtained with specimens with a low stiffness generally bias spot welded joints, especially in
the case of high strength steels.
The statistical significance of test results is influenced by their scatter. The larger the number of joints tested
under uniform loading in a single specimen, the smaller is the scatter. Therefore, in order to obtain results with
the same degree of significance, the number of specimens to be tested with two spot welds, for example, is
five times greater than H- or double disc specimens with 10 spot welds. Furthermore, the stiffness of flat
specimens is appreciably lower than that of components, so that the results obtained with these specimens
are generally misleading. In addition, some specimens cannot be subjected to compressive loads or negative
load ratios R, e.g. two flat specimens with one or two welds.

NOTE See Clause 4.
Figure 2 — Wöhler curves of spot-welded H-specimens of 1 mm DC 04 steel sheet subjected to shear
and peel loading, load ratio R = 0,1 (Reference [9])
ISO 18592:2009(E)
5.3 Specimen fabrication
5.3.1 Sheet material
The sheet material for the coupons may be in the sheared condition, but all burrs should be removed. Care
should be taken to ensure that the coupons are not bent or distorted. Specimens made using such coupons
may have an adverse effect on the test results and increase scatter. The dimensions of the coupons for the
different specimens are given in the relevant tables.
If the design under consideration uses extrusions or cast material, then the specimens should also be made
using extruded profiles or cast material, e.g. aluminium and magnesium alloys as required by the design.
The bending of the components of the specimens shall be performed in a press brake to the required bending
angle and radius, R = 2t. If the material employed does not allow this radius, it may be bent to R . Since
min max
the accuracy of the specimens depends on the dimensions of the coupons, ensure that the tolerances given in
the tables are strictly adhered to.
The components of the double disc specimen require the use of drawing- or deep-drawing tools for their
fabrication.
5.3.2 Bending and forming
The bending of the components of the specimens shall be performed in a press brake to the required bending
angle and radius, R = 2t. If the material employed does not allow this radius, it may be bent to the R .
min max
Since the accuracy of the specimens depends on the dimensions of the coupons, to ensure that the
tolerances given in the tables are strictly adhered to.
The components of the double disc specimen require the use of drawing- or deep-drawing tools for their
fabrication. Press forming tools, e.g. deep-drawing tools, should not be used for other than the double disc
specimens because the large number of process parameters, e.g. clamping force, blank holder geometry,
quantity and properties of lubricant, and surface roughness of tools, can influence the degree of work-
hardening, sheet thickness and surface conditions, and thus the properties of the specimens, making a
comparison of the results difficult.
The geometry of the specimens and the location, pitch and size of the spot welds may be modified such that
design and manufacturing requirements can be taken into consideration. For example, the pitch, the nugget
diameter, the flange width and the location of the weld on the flange can be modified if required. Suitable jigs
should be used for positioning the coupons during welding and ensuring a precise location of the welds and
uniform load distribution during testing.
The joining sequences for all specimens shall be from the centre of the specimen towards the edge, see
Figure 3. The welding sequence for the different multi-spot specimens shall be such that enveloping is
avoided. The diameter of all welds shall conform to the specifications. If necessary, increase the welding
current to compensate for the effect of shunting.
For AHS steels, much larger bending and drawing radii are necessary. In such cases, it is necessary to modify
the flange width and the location of the welds accordingly.

Figure 3 — Joining sequence for H-specimens
10 © ISO 2009 – All rights reserved

ISO 18592:2009(E)
5.3.3 Tolerances
The accurate fabrication of the test specimens is of great importance, as improper methods of preparation can
greatly bias the test results. More specifically, the tolerances should not exceed the values given in the tables
for the respective specimens. For H- and KS-2 specimens, the inside width, and for hat specimens, the
+0,2
outside width, each have a tolerance of mm. The flange angle is (90 ± 0,5)°.
5.3.4 Welding
All the parameters used for the fabrication of the specimens shall be documented (see ISO 15609-5:2004,
Annex A) in the test report.
If spot welding is used in combination with an adhesive, the name and type of adhesive, information on the
surface pre-treatment, curing temperature, etc. shall be included in the test report.
5.3.5 Storage
Specimens which are subjected to corrosion in air at room temperature should be protected accordingly,
preferably in an inert medium. The specimen should be removed from the storage medium before testing,
care being taken not to affect the specimen chemically.
5.3.6 Inspection
All the specimens shall be inspected before testing. Special attention should be paid to the geometry of the
specimens, i.e. width and flange angles and to the joints. A gauge is recommended for the overall check of the
dimensions.
5.4 Specimen geometry
5.4.1 General
The geometry of the specimens, and the location, pitch and size of the spot welds, should be modified such
that design and manufacturing requirements can be taken into consideration. For example, the pitch, the
nugget diameter, flange width, and the location of the weld on the flange can be modified if required. Suitable
jigs should be used for positioning the coupons during welding and ensuring a precise location of the welds.
Several specimens are currently used in fatigue tests. The aim of this International Standard is to help the
user to select specimens suitable for the task in hand:
a) single spot welded as specified in ISO 14273, see Figure 4;
b) flat overlap specimen with two spot welds, see Figure 5;
c) flat multi-spot specimens for shear and peel loads, see Figures 6 and 7;
d) H-specimens for shear and peel loading, see Figures 8 and 9;
e) single- and double hat specimens (under 4-point bending), see Figures 10 and 11;
f) various closed sections (under 4-point bending), see Figure 12;
g) double disc specimen, see Figure 13;
h) KS-2 specimen, see Figure 14.
The geometry and the dimensions of the different specimens are given in the corresponding figures and tables.
ISO 18592:2009(E)
5.4.2 Specimen geometry of flat specimens
The flat specimens listed in 5.4.1 a) and 5.4.1 b) have a stiffness which is much lower than that of normal
structures.
The flat specimens listed in 5.4.1 c) are stiffer and offer a number of advantages, allowing the influence of
parameters such as pitch, overlap and uniform and non-uniform stress distribution to be investigated. These
specimens require the use of the same grips as the H-specimens listed in 5.4.1 d).

Key
1 shim plates are used to avoid misalignment when clamping the test specimen
NOTE 1 See Clause 4.
NOTE 2 For specimens consisting of sheets with unequal thicknesses, t , t , the sheet thicknesses given in Table 1
1 2
correspond to those specified for the thinner sheet.
Figure 4 — Single spot specimen in accordance with ISO 14324
Table 1 — Dimensions of single spot specimen in accordance with ISO 14324
Dimensions in millimetres
Total length of Specimen length Length of single
Sheet thicknesses Width Overlap
a a
specimen between grips coupon
t , t b a l l l
1 2 S g t
0,5 u t u 1,5 45 ± 0,5 35 W 250 160 W 142,5
1,5 < t u 3,0 60 ± 0,5 46 W 320 200 W 182,5
3,0 < t u 6,0 90 ± 0,8 60 W 420 240 W 240
a
These dimensions are applicable for older test machines with mechanical clamps. Under this assumption, the length of the
clamped area l should be greater than the specimen width. For modern machines, in particular those with hydraulic clamps, the length
c
of the clamped area as well as l and l can be reduced correspondingly.
t S
12 © ISO 2009 – All rights reserved

ISO 18592:2009(E)
Key
1 shim plates are used to avoid misalignment when clamping the test specimen
NOTE 1 See Clause 4.
NOTE 2 For specimens consisting of sheets with unequal thicknesses, t , t , the sheet thicknesses given in Table 2
1 2
correspond to those specified for the thinner sheet.
Figure 5 — Flat overlap specimen with two spot welds
Table 2 — Dimension of flat overlap specimen with two spot welds
Dimensions in millimetres
Length of single Total length of Specimen length
Sheet thickness Width Overlap Pitch
coupon specimen between grips
a a
t , t b a l l l e
1 2 t S g
0,5 u t u 1,5 70 35 W 167,5 W 300 160 35
1,5 < t u 3,0 100 45 W 222,5 W 400 200 50
3,0 < t u 6,0 W 100 60 W 250 W 440 240 50
a
These dimensions are applicable for older test machines with mechanical clamps. Under this assumption, the length of the
clamped area l should be greater than the specimen width. For modern machines, in particular those with hydraulic clamps, the length
c
of the clamped area, as well as l and l , can be reduced correspondingly.
t S
ISO 18592:2009(E)
Dimensions in millimetres
NOTE See Clause 4.
Figure 6 — Flat multi-spot shear specimen
Table 3 — Dimensions of flat multi-spot shear specimen
Dimensions in millimetres
Smallest sheet Specimen length
Overlap
thickness between grips
t or t a l
1 2 g
u 1 16 40
u 1,5 18 42
u 2 21 45
u 3 27 51
u 4 34 58
u 5 39 63
14 © ISO 2009 – All rights reserved

ISO 18592:2009(E)
Dimensions in millimetres
Key
h = 42 + (r or r )
L 1 2
l = t + t + r + r + 6 (in millimetres)
g 1 2 1 2
NOTE See Clause 4.
Figure 7 — Flat multi-spot peel specimen
Table 4 — Dimensions of flat multi-spot peel specimen
Dimensions in millimetres
Smallest sheet
Overlap Edge distance Radius
thickness
a
t or t a l r or r
1 2 e 1 2
1 16 7 2 < r < 3
1,5 18 7,5 3 < r < 4,5
2 21 8,5 4 < r < 6
3 27 11 6 < r < 9
4 34 14 8 < r < 12
5 36,5 15 10 < r < 15
a
The bending radius for AHS steels may have to be increased. In this case, modifications
of overlap and other dimensions may be necessary.

ISO 18592:2009(E)
Dimensions in millimetres
Key
l = (2 l + a + t )
g a 1
h = a + l + 36 + t (in millimetres)
s a 1
h = 42 + (r or r )
U 1 2
NOTE See Clause 4.
Figure 8 — H-Shear specimen
Table 5 — Dimensions of shear multi-spot H-specimens
Dimensions in millimetres
Distance
Smallest sheet Specimen length
between grip Overlap Edge distance Radius
thickness between grips
and overlap
a
t or t l a l l r
1 2 a e g
u 1 12 16 7 40 + t 2 < r < 3
u 1,5 12 18 7,5 42 + t 3 < r < 4,5
u 2 12 21 8,5 45 + t 4 < r < 6
u 3 12 27 11 51 + t 6 < r < 9
u 4 12 34 14 58 + t 8 < r < 12
u 5 12 39 15 63 + t 10 < r < 15
a
The bending radius for AHS steels may have to be increased. In this case, modifications of overlap and other dimensions may be
necessar
...