Protective helmets - Test methods - Shock absorption including measuring rotational kinematics

The proposed standard will specify a test method for helmets that measures the translational and rotational kinematics in impacts of a helmeted head form against an anvil.

Schutzhelme - Prüfverfahren - Stoßdämpfung einschließlich Messung der Rotationskinematik

Dieses Dokument legt ein Prüfverfahren für Helme zur Messung der Translations- und Rotationskinematik beim Aufprall eines behelmten Prüfkopfes gegen einen Sockel fest

Casques de protection - Méthodes d'essai - Absorption des chocs avec mesure de la cinématique de rotation

Le présent document spécifie une méthode d'essai pour les casques, qui mesure les cinématiques de translation et de rotation lors d'impacts d'une fausse tête munie d'un casque contre une enclume.

Varovalne čelade - Preskusne metode - Absorpcija udarcev, vključno z merjenjem rotacijske kinematike

General Information

Status
Not Published
Publication Date
26-May-2024
Current Stage
4060 - Closure of enquiry - Enquiry
Start Date
27-Apr-2023
Due Date
13-Feb-2023
Completion Date
27-Apr-2023

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Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN 17950:2023
01-april-2023
Varovalne čelade - Preskusne metode - Absorpcija udarcev, vključno z merjenjem
rotacijske kinematike

Protective helmets - Test methods - Shock absorption including measuring rotational

kinematics
Schutzhelme - Prüfverfahren - Stoßdämpfung einschließlich Messung der
Rotationskinematik

Casques de protection - Méthodes d'essai - Absorption des chocs avec mesure de la

cinématique de rotation
Ta slovenski standard je istoveten z: prEN 17950
ICS:
13.340.20 Varovalna oprema za glavo Head protective equipment
oSIST prEN 17950:2023 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN 17950:2023
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oSIST prEN 17950:2023
DRAFT
EUROPEAN STANDARD
prEN 17950
NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2023
ICS 13.340.20
English Version
Protective helmets - Test methods - Shock absorption
including measuring rotational kinematics

Casques de protection - Méthodes d'essai - Absorption Schutzhelme - Prüfverfahren - Stoßdämpfung

des chocs avec mesure de la cinématique de rotation einschließlich Messung der Rotationskinematik

This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee

CEN/TC 158.

If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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-CENELEC

Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,

Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and

United Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are

aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without

notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 17950:2023 E

worldwide for CEN national Members.
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oSIST prEN 17950:2023
prEN 17950:2023 (E)
Contents Page

European foreword ............................................................................................................................................ 3

Introduction .......................................................................................................................................................... 4

1 Scope .......................................................................................................................................................... 6

2 Normative references .......................................................................................................................... 6

3 Terms and definitions ......................................................................................................................... 6

4 Prerequisites .......................................................................................................................................... 7

4.1 Parameters needed .............................................................................................................................. 7

4.2 Head form ................................................................................................................................................ 7

4.2.1 General...................................................................................................................................................... 7

4.2.2 External geometry ................................................................................................................................ 7

4.2.3 Head form specifications .................................................................................................................... 7

4.2.4 Outer surface specification ............................................................................................................... 8

4.2.5 Instrumentation .................................................................................................................................... 8

4.2.6 Instrumentation for measuring the head initial position ...................................................... 8

4.2.7 Markers .................................................................................................................................................... 9

4.2.8 Acquisition system verification ..................................................................................................... 10

4.2.9 Head form coefficient of friction verification test ................................................................... 10

5 Test method .......................................................................................................................................... 10

5.1 General.................................................................................................................................................... 10

5.2 Principle ................................................................................................................................................. 10

5.3 Apparatus .............................................................................................................................................. 10

5.3.1 Base .......................................................................................................................................................... 10

5.3.2 Anvil ......................................................................................................................................................... 10

5.3.3 Guidance system and helmet carrier ........................................................................................... 11

5.4 Procedure .............................................................................................................................................. 12

6 Test report ............................................................................................................................................. 12

Annex A (normative) Head form coefficient of friction verification test ..................................... 13

Annex B (normative) Test results – Uncertainty of measurement ................................................ 16

Bibliography ....................................................................................................................................................... 17

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oSIST prEN 17950:2023
prEN 17950:2023 (E)
European foreword

This document (prEN 17950:2023) has been prepared by Technical Committee CEN/TC 158 “Head

protection”, the secretariat of which is held by SIS.
This document is currently submitted to the CEN Enquiry.
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oSIST prEN 17950:2023
prEN 17950:2023 (E)
Introduction
0.1 Purpose and background

The test method described in this document is designed to measure translational and rotational

kinematics from any helmeted dynamic event such as an impact to an object. Statistics from bike, ski,

equestrian, and other accidents show that oblique impacts, resulting in a combination of translational

and rotational kinematics of the head, are more frequent than pure translational impacts. EN 13087-2,

Protective helmets — Test methods — Part 2: Shock absorption measures only the translational motion in

impacts against flat, hemispherical or curb stone anvils. A test method that measures the translational

and rotational kinematics is therefore important and much needed.

As this document specifies the measuring the translational and rotational kinematics, it is possible to use

this document as a complementary test method to EN 13087 2 when performing tests to measure shock

absorption of helmets.
This document does not replace EN 13087 2.
0.2 Background to the design of the test method

Preliminary discussions to start work on the test method specified in this document started in 2006. In

2013, the responsible working group within CEN/TC 158 Head protection, Head forms and test methods,

accelerated the work on the design of the test method.

Extensive efforts to ensure the soundest state-of-art test method have been made by:

— gathering data and scientific evidence from the widest range of scientific sources possible;

— performing multiple round robin tests;

— organizing numerous physical and online working group meetings in which a multitude of

alternatives were analysed and discussed exhaustively before finally opting for the final design

specified in this document;

— ensuring that experts within the field of biomechanics and brain understanding are members of the

working group.

As part of the CEN standardization process, the content of this document has been further scrutinized

and refined by other stakeholders and experts in the member countries of CEN.
0.3 Head form

A new head form without a neck for rotational impact tests has been developed for the test method

specified in this document. The main reasons for developing a new type of head form are described below:

a) analysis of the inertial properties (Mass, Moment of Inertia and Centre of Gravity) of the existing

EN 960 and Hybrid III head forms showed values that were very different from the values found in

literature from measurements of the human head. This is not surprising as the EN 960 head form

includes parts of a rigid neck, and the Hybrid III head form was developed for frontal car collisions

and not for helmet testing;

b) the new test method requires that the outer surface of the head form that comes in contact with the

helmet has more humanlike properties. Specifically, the coefficient of friction between the head form

and the inner surface in a helmet needs to be specified. Neither the EN 960 head form nor the

Hybrid III head form has the coefficient of friction chosen for the head form specification in this

document.
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prEN 17950:2023 (E)
0.4 Performance requirements and prerequisites

Performance requirements for pass/fail criteria when using the test method in this document will be

specified in the relevant helmet product standards. The writers of those documents will also specify test

prerequisites, see Clause 4 for details.
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oSIST prEN 17950:2023
prEN 17950:2023 (E)
1 Scope

This document specifies a test method for helmets that measures the translational and rotational

kinematics in impacts of a helmeted head form against an anvil.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements 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.

EN 12195-2, Load restraint assemblies on road vehicles - Safety - Part 2: Web lashing made from man-made

fibres

ISO 6487, Road vehicles — Measurement techniques in impact tests — Instrumentation

ISO 6344-2, Coated abrasives — Determination and designation of grain size distribution — Part 2:

Macrogrit sizes P12 to P220
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— IEC Electropedia: available at https://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
3.1
Tragion point
cephalometric point in the notch just above the tragus of the ear

Note 1 to entry: The Tragion point is part of defining the Frankfurt plane (3.2) and close to the external auditory

meatus.

Note 2 to entry: The Tragion point is illustrated in Figure 1 in 4.2.7 and is defined in the CAD files described in 4.2.2.

3.2
Frankfurt plane

longitudinal plane defined on the head form through the Tragion point (3.1) and the lower orbit of the

eye

Note 1 to entry: The Frankfurt Plane is similar to the Basic Plane defined in EN 960.

Note 2 to entry: The Frankfurt plane is illustrated in Figure 1 in 4.2.7.
3.3
Pilz plane

plane on the head form angled 10° from the reference plane at the rear of the head at the intersection of

the reference plane with the midsagittal plane
Note 1 to entry: The Pilz plane is illustrated in Figure 1 in 4.2.7.
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prEN 17950:2023 (E)
3.4
reference plane

for a given head form, when erect, the horizontal plane located at a vertical distance ‘y’ measured down

the central vertical axis from the centre of the crown
Note 1 to entry: All horizontal datum levels are quoted relative to this plane.
Note 2 to entry: The reference plane is illustrated in Figure 1 in 4.2.7.
[SOURCE: EN 960:2006, 2.5, modified – Note 2 to entry has been added.]
4 Prerequisites
4.1 Parameters needed
To perform the test method specified in t
...

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