ISO 16130:2015

INTERNATIONAL ISO
STANDARD 16130
First edition
2015-08-01
Aerospace series — Dynamic testing
of the locking behaviour of bolted
connections under transverse loading
conditions (vibration test)
Aéronautique et espace — Essai dynamique des caractéristiques
de freinage des éléments de fixation, dans des conditions de charge
transversale (essai de vibration)
Reference number
ISO 16130:2015(E)
©
ISO 2015

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ISO 16130:2015(E)

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ii © ISO 2015 – All rights reserved

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ISO 16130:2015(E)

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Test principle . 2
5 Apparatus . 3
5.1 Schematic overview of components . 3
5.2 Test machine description . 3
5.3 Apparatus requirements . 4
6 Test procedure . 4
7 Test settings . 5
8 Evaluation . 8
9 Documentation . 9
Bibliography .11
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ISO 16130:2015(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
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ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
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Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information.
The committee responsible for this document is ISO/TC 20, Aircraft and space vehicles, Subcommittee
SC 4, Aerospace fastener systems.
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INTERNATIONAL STANDARD ISO 16130:2015(E)
Aerospace series — Dynamic testing of the locking
behaviour of bolted connections under transverse loading
conditions (vibration test)
1 Scope
This International Standard applies to the dynamic testing of the locking behaviour of bolted
connections in order to investigate the self-loosening behaviour of fasteners for aerospace applications
and is mainly intended for development work.
As test apparatuses are different (e.g. stiffness distribution), testing in accordance with this
International Standard, therefore, does not allow an absolute statement to be made on the locking
behaviour of bolted assemblies under service loads.
Thus, the objective of this test is a comparative evaluation of locking elements under defined test
conditions.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 16047, Fasteners — Torque/clamp force testing
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 16047 and the following apply.
3.1
clamp force
F
axial tension acting on the bolt shank or compression acting on the clamped member
[SOURCE: ISO 16047:2005, 3.1; modified — without restriction “during tightening”]
3.2
ultimate clamp force
F
u
theoretical maximum clamp force under combined stress condition potentially induced before
bolt/nut failure
[SOURCE: ISO 16047:2005, 3.3, modified]
3.3
initial clamp force
F
M
clamp force after tightening of test specimen before test
3.4
relative clamp force loss
Y
 F 
Y =−1 *%100
 
 
F
M
 
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ISO 16130:2015(E)

3.5
number of load cycles
N
number of transverse movements of the glider plate of the apparatus
3.6
pitch diameter
D
2
d
2
diameter of the pitch cylinder or pitch cone
[SOURCE: ISO 5408:2009, 5.9, modified — without reference, without note]
3.7
minor diameter
D
1
d
1
d
3
diameter of an imaginary cylindrical or conical surface tangent to the roots of an external thread
and/or to the crests of an internal thread
[SOURCE: ISO 5408:2009, 5.3, modified — without references, without notes]
3.8
tightening torque
T
overall torque applied on nut or bolt head in tightening
[SOURCE: ISO 16047:2005, 3.4, modified — without substitutes]
3.9
self-locking torque
prevailing torque
torque to be applied to the nut or bolt to maintain its movement of rotation in relation to the associated
part, the assembly being under no axial load, and the nut-locking system being completely engaged with
the bolt (two pitches minimum protrusion, including the end chamfer)
[SOURCE: ISO 5858:1999, 3.15]
3.10
transverse displacement
t
s
transverse movement of the glider plate in both directions from fastener centre line
Note 1 to entry: It is expressed in millimetres.
4 Test principle
The fasteners under test are tightened in a vibration testing machine to achieve a defined clamp force,
F , and then subjected to dynamic transverse loading. No additional axial operating force is applied to
M
the fasteners.
The change in clamp force during the vibration test is measured.
The test terminates after a specified number of load cycles or upon fracture of the bolt, stabilization of
residual clamp force, or upon complete loss of clamp force.
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ISO 16130:2015(E)

5 Apparatus
5.1 Schematic overview of components
See Figure 1.
Clamp force sensor
Transverse force sensor
Evaluation unit
Vibration and data
testing machine recording device
(e.g. PC)
Displacement sensor
Load cycle sensor
Input drive
NOTE Transverse force sensor is optional.
Figure 1 — Schematic overview of components
5.2 Test machine description
The machine (see Figure 2 for an example of a vibration testing machine) essentially consists of e.g. a
motor drive or a hydraulic drive generating a transverse displacement in the test fixture.
The test fixture consists of a stationary base and a floating glider plate which acts as clamped members
in the bolted joint in which the fastener to be tested is installed. The glider plate contains a rotationally
immobilized washer (test washer). The stationary base accommodates a clamp force-sensor for
measuring the clamp force between the glider plate and the stationary base. In the force-sensor, a test
insert is used that it is locked to prevent it from rotating. The relative movement between the stationary
base and the glider plate is measured with a displacement sensor.
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ISO 16130:2015(E)

1 2 3 4 5 8
7
6
Key
1 infinitely adjustable eccentric 5/6 fastener test assembly
2 connecting rod 7 displacement sensor
3 transverse force sensor (optional) 8 clamp force sensor (axial)
4 connecting plate
Figure 2 — Example of a vibration testing machine
5.3 Apparatus requirements
The apparatus shall meet the following requirements.
a) The relative movement (transverse displacement) between the stationary base and glider plate
shall be infinitely variable, preferably during operation and adjusted through electronic control.
In the thread diameter range up to 25,4 mm, the clamped-up testing facility shall permit relative
movements of up to ±1,5 mm between the stationary base and the glider plate.
b) Testing frequency be
...