ASTM F3555-22

Standard Test Method for Measuring Impact Attenuation Characteristics of Helmets Under Induced Rotational Loading Using an Inclined Anvil

SIGNIFICANCE AND USE
4.1 The purpose of these test methods is to provide reliable and repeatable tests for the evaluation of various types of protective headgear when subjected to rotational loading. Use of these test methods in conjunction with the specific individual performance standards is intended to reduce the likelihood of serious injury and death resulting from impacts to the head sustained by individuals participating in sports, recreation, and other leisure activities in which protective headgear is worn.
SCOPE
1.1 This test method covers laboratory equipment, procedures, and basic requirements pertinent to testing the performance of helmets during rotational loading using an incline anvil. Deviations and additions to this test method will be specified, as required, in individual ASTM performance standards.  
1.2 Requirements—The helmet may be tested under one or more specified environmental conditions for impact attenuation (the limiting of impact forces) as a result of a vertical free-fall onto an incline anvil.  
1.3 Except where noted, the values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.4 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.  
1.5 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

• Status: Published
• Publication Date: 14-Jun-2022
• ICS: 13.340.20 - Head protective equipment
• Technical Committee: F08 - Sports Equipment, Playing Surfaces, and Facilities
• Drafting Committee: F08.53 - Headgear and Helmets

Overview

ASTM F3555-22 is the internationally recognized standard test method for measuring the impact attenuation characteristics of helmets under induced rotational loading using an inclined anvil. Developed by ASTM International, this standard establishes precise laboratory equipment, procedures, and basic requirements essential for reliably testing helmets' performance during rotational impacts. Its purpose is to provide consistent and repeatable assessments of protective headgear to reduce the risk of injury or death from head impacts sustained in sports, recreation, and other leisure activities.

Key Topics

• Rotational Loading Evaluation: The standard specifically addresses the helmet's response to rotational forces generated during oblique impacts, which are closely linked to brain injury risks.
• Laboratory Test Procedures: It details the use of an inclined steel anvil, specific headforms, data acquisition systems, and signal processing methods for measuring both linear and angular accelerations.
• Helmet Performance Assessment: The protocol allows for testing under a variety of controlled environmental conditions, ensuring helmets are evaluated in realistic scenarios.
• Data Collection and Signal Filtering: Requirements for instrumentation, data logging (minimum 10,000 Hz sampling rate), and signal filtering (following SAE J211 CFC 1000) are specified for accurate measurement and analysis.
• Result Calculation: Impact test duration, peak resultant linear and angular acceleration, and angular velocity are calculated as key metrics for helmet safety performance.
• Individual Performance Standards Compatibility: ASTM F3555-22 is designed to work in tandem with sport- or activity-specific performance standards, which define test conditions, pass/fail criteria, and reporting requirements.

Applications

• Sports and Recreation: The standard is critical in the design, testing, and certification of helmets for activities like cycling, football, hockey, baseball, and other sports where head protection is essential.
• Product Development and Quality Control: Manufacturers use this method to validate helmet impact attenuation performance, ensuring products meet regulatory and industry benchmarks.
• Research and Injury Prevention: Testing under rotational loading conditions aids researchers and engineers in understanding helmet safety and improving designs to mitigate both linear and rotational acceleration-induced injuries.
• Certification and Self-Certification: The procedure supports both third-party and manufacturer self-certification processes, promoting helmet safety and compliance.
• Global Trade and Standardization: By aligning with WTO Technical Barriers to Trade (TBT) principles, ASTM F3555-22 fosters international acceptance and comparability in helmet testing.

Related Standards

• SAE J211-1: Instrumentation for Impact Test – Part 1 outlines requirements for electronic instrumentation used in impact testing, referenced for data acquisition consistency.
• SAE J1727: Provides calculation guidelines for impact testing to ensure data accuracy and reliability.
• ISO 6344-2: Specifies grain size distribution for abrasive papers, relevant for preparing the inclined anvil's impact surface.
• UN/ECE 22.06: Reference for dimensional headform specifications and impact test methodologies used in international helmet standards.
• Other ASTM Helmet Standards: ASTM F1446 (Helmet Testing Standard), ASTM F2040 (Helmet standard for recreational snow sports), and others often reference or incorporate this test method for rotational impact scenarios.

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ASTM F3555-22 sets a foundation for rigorous, standardized helmet testing under rotational impact conditions. Helmet manufacturers, conformity assessment bodies, researchers, and regulatory authorities rely on this standard to enhance head protection, facilitate product innovation, and ultimately improve user safety in a variety of activities. Aligning with this method supports product credibility, regulatory compliance, and demonstrates a commitment to injury prevention and consumer protection.

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: F3555 − 22
Standard Test Method for
Measuring Impact Attenuation Characteristics of Helmets
Under Induced Rotational Loading Using an Inclined Anvil
This standard is issued under the fixed designation F3555; 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
This test method specifies equipment and procedures used for the evaluation of the impact
attenuation characteristics of helmets under induced rotational loading using an incline anvil. It is the
responsibility of each ASTM Committee to decide whether this test method is suitable for inclusion
in their particular head protection standard. Individual ASTM performance standards (standard
specifications) may use these procedures and equipment and may specify test conditions, pass-fail
criteria, and other applicable performance requirements tailored to the needs of a particular activity
(for example, hockey, football, baseball, etc.). This test method was developed using resources in
medical, scientific, mechanical engineering, human factors, and biomechanical fields. However, it is
recognized that it is not possible to write a performance standard that will include all possible impact
scenarios. It is also recognized that serious injury or death can result from both low and high-energy
impacts, even when a helmet is worn. This test method incorporates aspects of other recognized
protectiveequipmentperformancestandards.Itdrawsfromworkdonebyotherswhereappropriatefor
this test method. These standards are referenced within this standard test method. It should be noted
that this test method specifies laboratory tests of helmets to measure its ability to reduce impact forces
applied to the head and other selected parameters during normal use for the given activity.
1. Scope priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
1.1 This test method covers laboratory equipment,
1.5 This international standard was developed in accor-
procedures, and basic requirements pertinent to testing the
dance with internationally recognized principles on standard-
performance of helmets during rotational loading using an
ization established in the Decision on Principles for the
incline anvil. Deviations and additions to this test method will
Development of International Standards, Guides and Recom-
be specified, as required, in individual ASTM performance
mendations issued by the World Trade Organization Technical
standards.
Barriers to Trade (TBT) Committee.
1.2 Requirements—The helmet may be tested under one or
2. Referenced Documents
more specified environmental conditions for impact attenua-
tion (the limiting of impact forces) as a result of a vertical 2.1 SAE Standards:
free-fall onto an incline anvil. SAE J211-1 Instrumentation for Impact Test – Part 1 –
Electronic Instrumentation
1.3 Except where noted, the values stated in SI units are to
SAE J1727 Calculation Guidelines for Impact Testing
be regarded as the standard. The values given in parentheses
2.2 ISO Standard:
are for information only.
ISO 6344-2 CoatedAbrasives – Determination and designa-
1.4 This standard does not purport to address all of the
tionofgrainsizedistribution–Part2:MacrogritsizesP12
safety concerns, if any, associated with its use. It is the
to P220
responsibility of the user of this standard to establish appro-
3. Terminology
3.1 Definitions:
This test method is under the jurisdiction of ASTM Committee F08 on Sports
Equipment, Playing Surfaces, and Facilities and is the direct responsibility of Available from SAE International (SAE), 400 Commonwealth Dr.,Warrendale,
Subcommittee F08.53 on Headgear and Helmets. PA 15096, http://www.sae.org.
Current edition approved June 15, 2022. Published July 2022. DOI: 10.1520/ Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
F3555-22. 4th Floor, New York, NY 10036, http://www.ansi.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F3555 − 22
3.1.1 alpha (α), n—abbreviation for angular acceleration, 6. Test Methodology
expressed in units of radians per second-squared.
6.1 Test Apparatus—The test apparatus shall consist of the
3.1.2 area of coverage, n—a specified area of the protective
following components and characteristics.
device that is intended to provide protection and is subject to
6.1.1 Impact Base—The impact base (see Fig. 1 Part C)
specific testing.
shall be solid and made of steel or a combination of steel and
concrete.Thebaseshallhaveamassofatleast500kg.Atleast
3.1.3 coronal plane, n—an anatomical plane perpendicular
the uppermost 25 mm shall consist of steel, which shall be
to both the basic and midsagittal planes and containing the
firmly attached to the concrete if present.
midpoint of a line connecting the left and right auditory
6.1.2 Test Anvil—Unless otherwise specified in the indi-
meatuses.
vidual performance standard, the test anvil shall consist of a
3.1.4 Frankfort plane, n—a plane connecting the highest
solid steel cylinder with a minimum diameter of 130 mm. The
point of the opening of the external auditory canal with the
cylinder shall include a minimum 130 mm diameter impact
lowest point on the lower margin of the orbit.
face that has a 45 6 0.5° angle from the horizontal plane (see
3.1.5 helmet carrier, n—a device designed to carry the test
Fig. 1 PartA).The minimum height of the steel region beneath
headform and test helmet along the guided rail system toward
the impact face shall be 30 mm (see Fig. 1 Dimension h). The
the incline anvil and to release the test headform and test
minimum height between the impact base and the test anvil
helmet immediately prior to impact with the incline anvil.
shall be 200 mm (see Fig. 1 Part B) and the length/diameter
3.1.6 helmet position index (HPI), n—the vertical distance ratio of Part B shall not be greater than five. Unless otherwise
from the brow of the helmet to the headform reference plane
specified in the individual performance standard, the impact
when the helmet is placed on the reference headform. face of the test anvil shall be covered with an abrasive paper,
with a grain size distribution of P80 according to ISO 6344-2.
3.1.7 midsagittal plane, n—ananatomicalplaneperpendicu-
The abrasive paper shall be securely attached to the anvil to
lar to the basic plane and containing the midpoint of the line
avoid slippage. Unless otherwise specified in the individual
connecting the notches of the right and left inferior orbital
performance standard, the abrasive paper shall be replaced
ridgesandthemidpointofthelineconnectingthesuperiorrims
after three single tests or if significant damage occurs.
of the right and left auditory meatuses.
6.1.3 Guidance System and Helmet Carrier—The guidance
3.1.8 nine accelerometer package (NAP), n—a practical
systemshallprovideforthepositioningofanyinitialheadform
method for calculating rotational acceleration inside a manikin
angleandimpactpointonthehelmetverticallyabovetheanvil.
headform, including geometric corrections due to accelerom-
Details regarding the position and orientation of the headform
eter placements, as described by diMasi (1995).
and helmet shall be provided in the individual performance
3.1.9 omega (ω), n—abbreviation for angular velocity, ex-
standard. The guidance system shall be attached to the helmet
pressed in units of radians per second.
carrier in a manner that keeps the helmet in the target impact
3.1.10 tragion, n—the superior point on the juncture of the position during the raising, release and dropping of the
cartilaginous flap (tragus) of the ear with the head. headform/helmet assembly. The helmet carrier shall be de-
signedinamannerthatitdoesnotinfluencetheresponseofthe
4. Significance and Use headform/helmet assembly during the impact with the test
anvil.
4.1 The purpose of these test methods is to provide reliable
6.1.4 Impact Velocity—The headform/helmet assembly ver-
and repeatable tests for the evaluation of various types of
tical impact velocity shall be measured at a distance not more
protective headgear when subjected to rotational loading. Use
than 40 mm prior to the impact.The target impact velocity and
of these test methods in conjunction with the specific indi-
allowable tolerance shall be specified in the designated stan-
vidual performance standards is intended to reduce the likeli-
dard.
hood of serious injury and death resulting from impacts to the
6.1.5 Test Headforms—The test headforms used with this
head sustained by individuals participating in sports,
specificationshallbefullsizeheadformsthatarelistedinTable
recreation, and other leisure activities in which protective
1 and meet the dimensional specifications of Annex 6 of the
headgear is worn.
5,6
UN/ECE 22.06 standard. The external surface of each test
headform shall have a coefficient of friction of 0.27 to 0.33
5. Certification
5.1 Unless otherwise specified in the individual perfor-
mance standard, these test methods permit self-certification. It
UnitedNations,EconomiccommissionforEurope,workingpartyWP29onthe
Construction of Vehicles, Regulation No. 22, Uniform provisions concerning the
is recommended that each manufacturer employ an indepen-
approval of protective helmets for drivers and passengers of motorcycles and
denttestlaboratoryatleastannuallytotesteachmodelandsize
mopeds, Geneva, Initially passed 1958, amendment 03 1988, amendment 04 1995,
of head protection product offered for sale.
amendment 05 1999, amendment 06 2020.
The sole source of supply of the test headforms known to the committee at this
time is Cellbond, a division of Encocam Limited, 5 Stukeley Business Centre,
Blackstone Road, Huntingdon, Cambridgeshire, PE29 6EF, United Kingdom
DiMasi, F.P., Transformation of Nine-Accelerometer-Package (NAP) Data for ([e-mail]). If you are aware of alternative suppliers, please provide this
Replicating Headpart Kinematics and Dynamic Loading: Technical Report DOT information to ASTM International Headquarters. Your comments will receive
HS-808 282. Washington, DC, United States Department of Transportation, Na- careful consideration at a meeting of the responsible technical committee, which
tional Highway Traffic Safety Administration, 1995. you may attend.
F3555 − 22
Where:
d = minimum of 130 mm
h = minimum of 30 mm
θ=45 6 0.5°
FIG. 1 Typical Inclined Anvil Impact Base and Test Anvil
TABLE 1 Inclined Anvil Impact Test Headform Properties (Right Hand Coordinate System)
Center of Gravity (CG) Moment of Inertia (MOI)
Size Designation Mass including
(Circumference in instrumentation B B B
I I I
cg cg cg xx yy zz
x y z
A
2 C 2 C 2 C
mm) (kg) (mm) (mm) (mm)
(kg cm ) (kg cm ) (kg cm )
495 2.47 4.0 0.0 28.8 61.88 8.81 70.22
535 3.35 6.5 0.0 27.9 130.68 148.36 110.80
575 4.23 9.0 0.0 26.9 199.47 214.92 151.37
595 4.67 10.3 0.0 26.4 233.87 248.20 171.65
615 5.11 11.6 0.0 26.0 268.26 281.48 191.94
635 5.55 12.8 0.0 25.5 302.66 314.75 212.22
A
Tolerance ± 2%.
B
Tolerance ± 2 mm. Center of gravity locations are expressed relative to the tragion which is located on the Frankfort plane.
C
Tolerance ± 5%.
which is equal to an average force gauge measurement of not (2) The polyester strap shall be positioned over the test
less than 30 N and not more than 33 N when tested according headformalongthemidsagittalplaneoftheheadformsuchthat
to the procedures listed in 6.1.5.1.All headforms available for at one end of the strap a mass of 2 kg 6 25 g shall be attached,
testing shall have the inertial properties specified in Table 1. andattheotherendaforcegaugeshallbeattached(seeFig.2).
6.1.5.1 Headform Surface Coeffıcient of Friction Test Pro- Oncethemassandtheforcegaugehavebeenattached,pullthe
cedure: strap a distance of not less than 40 mm with a constant speed
(1) The test headform shall be positioned so th
...