ASTM D8101/D8101M-18

Standard Test Method for Measuring the Penetration Resistance of Composite Materials to Impact by a Blunt Projectile

SIGNIFICANCE AND USE
5.1 Advanced composite systems are used in a number of applications as shields to prevent penetration by projectiles. In general, the use of composites is more effective for blunt, rather than sharp, projectiles or in hybrid systems in which an additional shield can be used to blunt a sharp projectile. Knowledge of the penetration impact resistance of different material systems or the effects of environmental or in-service load exposure to the penetration resistance of given materials is useful for product development and material selection.  
5.2 An impact test used to measure the penetration resistance of a material can serve the following purposes:  
5.2.1 To quantify the effect of fiber architecture, stacking sequence, fiber and matrix material selection, and processing parameters on the penetration resistance of different composite materials;  
5.2.2 To measure the effects of environmental or in-service load exposure on the penetration impact resistance of a given material system; and  
5.2.3 As a tool for quality assurance requirements for materials designed for penetration resistance applications.  
5.3 The penetration resistance values obtained with this test method are most commonly used in material specification and selection and research and development activities. The data are not intended for use in establishing design allowables, as the results are specific to the geometry and physical conditions tested and are not generally scalable to other configurations.  
5.4 The reporting section requires items that tend to influence the penetration resistance of material systems. These include the following: fiber and matrix materials, fiber architecture, layup sequence, methods of material fabrication, environmental exposure parameters, specimen geometry and overall thickness, void content, specimen conditioning, testing environment and exposure time, specimen fixture and alignment, projectile mass and geometry, and projectile orientation at impact. Addit...
SCOPE
1.1 This test method measures the resistance of flat composite panels in one specific clamping configuration to penetration by a blunt projectile in free flight. In this test method, the term “penetration” is defined as the case in which the projectile travels completely through the composite panel and fully exits the back side. The composite materials may be continuous fiber angle-ply, woven or braided fiber-reinforced polymer matrix composites, or chopped fiber-reinforced composites. The resistance to penetration is quantified by a statistical function that defines the probability of penetration for a given kinetic energy.  
1.2 This test method is intended for composite test panels in which the thickness dimension is small compared with the test panel width and length (span to thickness on the order of 40 or greater).  
1.3 This test method is intended for applications such as jet engine fan containment, open rotor engine blade containment, or other applications in which protection is needed for projectiles at velocities typically lower than seen in ballistic armor applications. The typical impact velocity that this test is intended for is in the range of 100 to 500 m/s [300 to 1500 ft/s], as opposed to higher velocities associated with armor penetration.  
1.4 A flat composite panel is fixed between a circular-shaped clamping fixture and a large base fixture each with a large coaxial hole defining a region of the panel that is subjected to impact in the direction normal to the plane of the flat panel by a blunt projectile. Clamping pressure is provided by 28 through bolts that pass through the front clamp, the test specimen, and the back plate. The mass, geometry, desired impact kinetic energy, and impact orientation of the projectile with respect to the panel are specified before the test. Equipment and procedures are required for measuring the actual impact velocity and orientation during the test. The impact pe...

General Information

• Status: Published
• Publication Date: 14-Oct-2018
• ICS: 49.025.40 - Rubber and plastics
• Technical Committee: D30 - Composite Materials
• Drafting Committee: D30.05 - Structural Test Methods

Relations

• Replaces: ASTM D8101/D8101M-17 - Standard Test Method for Measuring the Penetration Resistance of Composite Materials to Impact by a Blunt Projectile
• Effective Date: 15-Oct-2018
• Refers: ASTM D883-24 - Standard Terminology Relating to Plastics
• Effective Date: 01-Feb-2024
• Refers: ASTM D883-23 - Standard Terminology Relating to Plastics
• Effective Date: 01-Nov-2023
• Refers: ASTM D5229/D5229M-20 - Standard Test Method for Moisture Absorption Properties and Equilibrium Conditioning of Polymer Matrix Composite Materials
• Effective Date: 01-Mar-2020
• Refers: ASTM D883-20 - Standard Terminology Relating to Plastics
• Effective Date: 01-Jan-2020
• Refers: ASTM D3878-19a - Standard Terminology for Composite Materials
• Effective Date: 15-Oct-2019
• Refers: ASTM D883-19c - Standard Terminology Relating to Plastics
• Effective Date: 01-Aug-2019
• Refers: ASTM D883-19a - Standard Terminology Relating to Plastics
• Effective Date: 15-Apr-2019
• Refers: ASTM D3878-19 - Standard Terminology for Composite Materials
• Effective Date: 15-Apr-2019
• Refers: ASTM D883-19 - Standard Terminology Relating to Plastics
• Effective Date: 01-Feb-2019
• Refers: ASTM D883-18a - Standard Terminology Relating to Plastics
• Effective Date: 01-Dec-2018
• Refers: ASTM D883-18 - Standard Terminology Relating to Plastics
• Effective Date: 01-Nov-2018
• Refers: ASTM D3878-18 - Standard Terminology for Composite Materials
• Effective Date: 01-Apr-2018
• Refers: ASTM D883-17 - Standard Terminology Relating to Plastics
• Effective Date: 15-Aug-2017
• Refers: ASTM E2533-17 - Standard Guide for Nondestructive Testing of Polymer Matrix Composites Used in Aerospace Applications
• Effective Date: 01-Jun-2017

Overview

ASTM D8101/D8101M-18: Standard Test Method for Measuring the Penetration Resistance of Composite Materials to Impact by a Blunt Projectile establishes procedures to evaluate how composite panels resist penetration by blunt projectiles. This critical standard, developed by ASTM International, is especially relevant for industries where composite materials serve as protective shields. The test quantifies the probability that a projectile will fully penetrate a composite panel, providing valuable data for material selection, product development, and research-not for establishing structural design allowables.

Key Topics

• Purpose of the Test Method: Determines the resistance of flat polymer matrix composite panels to full penetration by a blunt projectile.
• Composite Materials Covered: Applies to continuous fiber angle-ply, woven or braided fiber-reinforced, and chopped fiber-reinforced polymer matrix composite panels.
• Test Configuration:
  • Panels are mounted in a specific clamping fixture.
  • Projectiles are accelerated in free flight to impact the panel at specified velocities (100–500 m/s [300–1500 ft/s]).
  • Penetration is defined as complete travel through the panel with the projectile exiting the back side.
• Data Evaluation:
  • The results are expressed as a statistical function, typically the probability of penetration versus impact kinetic energy.
  • Multiple variables such as fiber architecture, layup sequence, matrix selection, specimen conditioning, and environmental factors are recorded.
• Scope Limits: The test results are specific to the tested configuration and not universally scalable to other geometries or conditions.

Applications

• Impact Shielding in Aerospace & Industrial Sectors: Used to assess materials for jet engine fan containment, open rotor blade containment, and other protective applications involving lower-velocity projectiles, as opposed to high-velocity ballistic threats.
• Material Specification and Quality Assurance: Supports material screening, comparison, and validation processes in the development phase, helping stakeholders choose optimal composite systems based on real impact resistance data.
• Environmental and In-Service Assessment: Determines how factors such as humidity, temperature, and service loads affect the composite’s penetration resistance, informing maintenance schedules and lifecycle management.
• Research & Development: Aids in quantifying the influence of fabrication methods and design parameters for new composite material innovations or improvements.

Related Standards

• ASTM A36/A36M – Specification for Carbon Structural Steel (used for test fixtures).
• ASTM D792 – Test Methods for Density and Specific Gravity of Plastics.
• ASTM D883 – Terminology Relating to Plastics.
• ASTM D3171 – Test Methods for Constituent Content of Composite Materials.
• ASTM D3878 – Terminology for Composite Materials.
• ASTM D5229/D5229M – Test Method for Moisture Absorption and Equilibrium Conditioning.
• ASTM D5687/D5687M – Guide for Preparation of Flat Composite Panels.
• ASTM E2533 – Guide for Nondestructive Testing of Polymer Matrix Composites.
• NIJ Standard 0101.06 – Ballistic Resistance of Body Armor (listed as a referenced standard for comparative purposes).

Practical Value

Implementing ASTM D8101/D8101M-18 ensures:

• Consistent and Reproducible Testing: Harmonized procedures improve comparability of results between labs and test series.
• Informed Material Selection: Provides quantifiable data on penetration resistance for determining the best composite systems for protective applications.
• Risk Mitigation: Helps prevent overestimating a material’s protective capabilities by ensuring tests reflect specific use conditions.
• Documentation for Compliance: Facilitates adherence to supplier/customer requirements and regulatory needs in safety-critical fields.

Keywords: ASTM D8101, composite material penetration resistance, blunt projectile impact test, polymer matrix composites, impact resistance, aerospace shielding, material specification, composite quality assurance, protective composites, penetration test method.

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: D8101/D8101M − 18
Standard Test Method for
Measuring the Penetration Resistance of Composite
Materials to Impact by a Blunt Projectile
This standard is issued under the fixed designation D8101/D8101M; 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.
1. Scope ment and procedures are required for measuring the actual
impact velocity and orientation during the test. The impact
1.1 This test method measures the resistance of flat com-
penetration resistance can be quantified by either the velocity
posite panels in one specific clamping configuration to pen-
or kinetic energy required for the projectile to penetrate the test
etration by a blunt projectile in free flight. In this test method,
panel fully.Anumber of tests are required to obtain a statistical
the term “penetration” is defined as the case in which the
probability of penetration for given impact conditions.
projectile travels completely through the composite panel and
fully exits the back side. The composite materials may be
1.5 This test method measures the penetration resistance for
continuous fiber angle-ply, woven or braided fiber-reinforced
a specific projectile and test configuration and can be used to
polymer matrix composites, or chopped fiber-reinforced com-
screen materials for impact penetration resistance, compare the
posites. The resistance to penetration is quantified by a
impact penetration resistance of different composite materials
statistical function that defines the probability of penetration
under the same test geometry conditions, or assess the effects
for a given kinetic energy.
of in-service or environmental exposure on the impact penetra-
1.2 This test method is intended for composite test panels in tion resistance of materials.
which the thickness dimension is small compared with the test
1.6 The impact penetration resistance is highly dependent
panel width and length (span to thickness on the order of 40 or
onthetestpanelmaterialsandarchitecture,projectilegeometry
greater).
and mass, and panel boundary conditions. Results are not
1.3 This test method is intended for applications such as jet
generally scalable to other configurations but, for the same test
engine fan containment, open rotor engine blade containment,
configurations, may be used to assess the relative impact
or other applications in which protection is needed for projec-
penetration resistance of different materials and fiber architec-
tiles at velocities typically lower than seen in ballistic armor
tures.
applications. The typical impact velocity that this test is
1.7 The values stated in either SI units or inch-pound units
intendedforisintherangeof100to500m/s[300to1500ft/s],
are to be regarded separately as standard. The values stated in
as opposed to higher velocities associated with armor penetra-
each system may not be exact equivalents; therefore, each
tion.
system shall be used independently of the other. Combining
1.4 A flat composite panel is fixed between a circular-
values from the two systems may result in nonconformance
shaped clamping fixture and a large base fixture each with a
with the standard. Within the text, the inch-pound units are
large coaxial hole defining a region of the panel that is
shown in brackets.
subjected to impact in the direction normal to the plane of the
flat panel by a blunt projectile. Clamping pressure is provided 1.8 This standard does not purport to address all of the
by 28 through bolts that pass through the front clamp, the test safety concerns, if any, associated with its use. It is the
specimen, and the back plate. The mass, geometry, desired responsibility of the user of this standard to establish appro-
impact kinetic energy, and impact orientation of the projectile priate safety, health, and environmental practices and deter-
with respect to the panel are specified before the test. Equip- mine the applicability of regulatory limitations prior to use.
1.9 This international standard was developed in accor-
dance with internationally recognized principles on standard-
This test method is under the jurisdiction of ASTM Committee D30 on
Composite Materials and is the direct responsibility of Subcommittee D30.05 on
ization established in the Decision on Principles for the
Structural Test Methods.
Development of International Standards, Guides and Recom-
Current edition approved Oct. 15, 2018. Published February 2019. Originally
mendations issued by the World Trade Organization Technical
approved in 2017. Last previous edition approved in 2017 as D8101/D8101M – 17.
DOI: 10.1520/D8101_D8101M-18. Barriers to Trade (TBT) Committee.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D8101/D8101M − 18
2. Referenced Documents 3.2.5 Impact Penetration Resistance (IPR), n—the kinetic
2 energy (or associated impact velocity) of a projectile corre-
2.1 ASTM Standards:
sponding to the 50 % probability of penetration.
A36/A36M Specification for Carbon Structural Steel
3.2.6 reference coordinate system, n—coordinate system
D792 Test Methods for Density and Specific Gravity (Rela-
defined for the purpose of identifying the impact velocity and
tive Density) of Plastics by Displacement
orientation of the projectile and the orientation of the test
D883 Terminology Relating to Plastics
specimen.
D3171 Test Methods for Constituent Content of Composite
Materials
3.2.6.1 Discussion—An example of a reference coordinate
D3878 Terminology for Composite Materials
system is one in which the X direction is normal to the plane of
D5229/D5229M TestMethodforMoistureAbsorptionProp-
the flat panel with positive values measured in the direction of
erties and Equilibrium Conditioning of Polymer Matrix
the projectile travel, the Y direction is in the plane of the flat
Composite Materials
test panel and is horizontal with positive values measured to
D5687/D5687M Guide for Preparation of Flat Composite
the right when viewing the panel from the impacted side, and
Panels with Processing Guidelines for Specimen Prepara-
the Z direction is vertical with positive values measured
tion
downward and the origin is at the center of the panel on the
E2533 Guide for Nondestructive Testing of Polymer Matrix
impacted face. The reference coordinate system is defined by
Composites Used in Aerospace Applications
the organization conducting the tests.
3 -1
2.2 NIJ Standard: 3.2.7 residualvelocity,Vr[LT ],n—absolutevelocityofthe
NIJ Standard 0101.06 Body Amor—Ballistic Resistance
projectile just after penetration (if penetration occurs).
3.3 Symbols:
3. Terminology 2 -2
3.3.1 E [ML T ]—Loss in kinetic energy of the projectile
a
as a result of the impact.
3.1 Definitions—In Terminology D3878, terms are defined
2 -2
relating to composite materials. In Terminology D883, terms
3.3.2 E [ML T ]—Kinetic energy of the projectile at the
i
aredefinedrelatedtoplastics.Intheeventofaconflictbetween
time of impact.
terms, Terminology D3878 shall have precedence over the
2 -2
3.3.3 E [ML T ]—Kinetic energy of the projectile after
r
other standards.
penetrating the test panel (if penetration occurs).
3.2 Definitions of Terms Specific to This Standard: If the
3.3.4 M[M]—Projectile mass.
term represents a physical quantity, its analytical dimensions
are stated immediately following the term (or letter symbol) in
4. Summary of Test Method
fundamental dimension form, using the following ASTM
4.1 An impact test is performed by accelerating a defined
standard symbology for fundamental dimensions, shown
projectile to a specified velocity, typically with the use of a
within square brackets: [M] for mass, [L] for length, [T] for
single-stage gas gun, into a composite test panel that is
time, [θ] for thermodynamic temperature, and [nd] for non-
supported in a fixture. The test panel is supported in a circular
dimensional quantities. Use of these symbols is restricted to
fixture with precision bolts extending through a front clamp
analytical dimensions when used with square brackets, as the
and the specimen itself to avoid slipping of the specimen at the
terms may have other definitions when used without the
boundaries.Thelocationoftheholesisremotefromtheimpact
brackets.
-1 site so that damage is not initiated at the holes. Depending on
3.2.1 impact velocity, Vi [LT ], n—velocity of the projectile
the kinetic energy of the projectile, it may or may not damage
in the direction of projectile travel just before impact.
or penetrate the test panel. The penetration resistance is
3.2.2 penetrate, v—to travel fully through a body and
quantified by either the velocity or kinetic energy required to
emerge completely on the other side.
penetratethetestpanel.Thepenetrationresistanceisafunction
3.2.3 projectile face, n—front portion of the projectile that of the geometry and materials of the test panel. Comparisons
first comes into contact with the test panel.
between materials or material conditions cannot be made
unlessidenticaltestconfigurationsandtestconditionsareused.
3.2.4 projectile orientation, n—angular position of the pro-
jectile as determined by a set of measurements relative to the 4.2 Procedures and equipment for measuring the impact
reference coordinate system.
velocity and orientation of the projectile just before impact are
3.2.4.1 Discussion—Typically used to define the angular required. Equipment for measuring the residual velocity of the
position of the projectile just before impact with the test projectile after penetration, if it occurs, is desirable but not
specimen. required.
5. Significance and Use
5.1 Advanced composite systems are used in a number of
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
applications as shields to prevent penetration by projectiles. In
Standards volume information, refer to the standard’s Document Summary page on
general, the use of composites is more effective for blunt,
the ASTM website.
rather than sharp, projectiles or in hybrid systems in which an
Available from the National Institute of Justice,Washington, DC, www.nij.gov/
publications. additional shield can be used to blunt a sharp projectile.
D8101/D8101M − 18
Knowledge of the penetration impact resistance of different stackingsequencealignment,anddamageinducedbyimproper
material systems or the effects of environmental or in-service specimen machining are known causes of high material data
loadexposuretothepenetrationresistanceofgivenmaterialsis scatter in composites in general. Important aspects of panel
useful for product development and material selection. specimen preparation that contribute to data scatter include
thickness variation and out-of-plane curvature.
5.2 An impact test used to measure the penetration resis-
tance of a material can serve the following purposes:
6.3 Impact Location and Projectile Orientation—The loca-
5.2.1 To quantify the effect of fiber architecture, stacking
tion of the projectile impact shall occur at the center of the
sequence, fiber and matrix material selection, and processing
panel for results to be valid. Lack of control over the impact
parameters on the penetration resistance of different composite
location will produce scatter in the results and invalidate
materials;
comparisons between different materials or environmental
5.2.2 To measure the effects of environmental or in-service
exposure conditions. The orientation of the projectile shall be
load exposure on the penetration impact resistance of a given
such that its center of mass is aligned with the impact direction
material system; and
and the impact direction is normal to the plane of the test
5.2.3 As a tool for quality assurance requirements for
specimen. Differences in projectile orientation between tests
materials designed for penetration resistance applications.
will lead to data scatter.
5.3 The penetration resistance values obtained with this test
6.4 Support Fixture Characteristics—Results are affected
method are most commonly used in material specification and
by the dimensions, as well as the corresponding mass and
selection and research and development activities.The data are
rigidity of the support fixture. Bolt torque differences will
not intended for use in establishing design allowables, as the
affect the boundary conditions and lead to inconsistent results.
results are specific to the geometry and physical conditions
The support fixture shall be significantly more rigid than the
tested and are not generally scalable to other configurations.
test specimen for results to be valid.
5.4 The reporting section requires items that tend to influ-
6.5 Impact Device Characteristics—The method of acceler-
ence the penetration resistance of material systems. These
ating the projectile will affect the repeatability of the projectile
include the following: fiber and matrix materials, fiber
impact velocity and orientation. Lack of control over repeat-
architecture, layup sequence, methods of material fabrication,
ability will require a greater number of tests to ensure
environmental exposure parameters, specimen geometry and
statistically valid results are obtained.
overall thickness, void content, specimen conditioning, testing
environment and exposure time, specimen fixture and
6.6 Velocity and Orientation Measurement Equipment—
alignment, projectile mass and geometry, and projectile orien-
Valid results are directly dependent on the accuracy of the
tationatimpact.Additionalreportingrequirementsincludesize
velocity and orientation measurements.
and description of damage, results of any pre- and post-test
6.7 Damage Modes—Damage mode differences between
nondestructive inspection, impact velocity, accuracy of the
materials will affect the evaluation of results. Widespread
velocity measurement apparatus, and whether or not the
damage that extends to the specimen boundaries may invali-
projectile penetrated the panel. Residual velocity is a desirable,
date results.
but not a necessary, value to be reported.
5.5 The reporting section shall also include the parameters 6.8 Nondestructive Inspection—Nondestructive testing
(NDT) results are affected by a number of factors, including
of a statistical function that gives the probability of penetration
as a function of impact kinetic energy (see 14.4). the particular Practice or Test Method used, the inherent
variability of the NDT Practice or Test Method, and the
5.6 The relevant measurements that result from the impact
experience of the operator.
test are the kinetic energy and impact velocity of the projectile
and whether or not the projectile penetrated the specimen. An
7. Apparatus
optional item to be measured is the loss in kinetic energy of the
projectile as a function of impact velocity if measurements of
7.1 Micrometers and Calipers—A micrometer witha4to
the residual velocity are recorded.
7 mm[0.16to0.28in.]nominaldiameterballinterfaceoraflat
anvil interface shall be used to measure the specimen thick-
6. Interferences
ness. A ball interface is recommended for thickness measure-
6.1 The impact penetration resistance is dependent on many
ments when at least one surface is irregular (for example, a
factors, such as test specimen thickness, areal density, fiber
coarse peel ply surface that is neither smooth nor flat). A
architecture, fiber and matrix materials, fiber volume ratio,
micrometer or caliper with a flat anvil interface shall be used
pre-test environmental and load exposure, test environment,
for measuring length, width, and other machined surface
boundary conditions, projectile geometry, and projectile mass.
dimensions. The use of alternative measurement devices is
Consequently, comparisons cannot be made between materials
permitted if specified (or agreed to) by the test requestor and
unless identical test configurations, test conditions, and mate-
reported by the testing laboratory. The accuracy of the instru-
rial thickness are used. Therefore, all deviations from the
ment(s) shall be suitable for reading to within 1 % of the
standard test configuration shall be reported in the results.
specimen dimensions. For typical specimen geometries, an
6.2 Materials and Specimen Preparation—Poor material instrument with an accuracy of 60.0025 mm [60.0001 in.] is
fabrication practices, lack of control of fiber placement and adequateforthicknessmeasurements,whileaninstrumentwith
D8101/D8101M − 18
an accuracy of 60.025 mm [60.001 in.] is adequate for vessel, a burst valve, and a gun barrel aimed at the test
measurement of length, width, and other machined surface specimen. For safety, the test specimen should be located
dimensions. inside of a closed containment structure vented to allow
pressure in the structure to be released. The device shown in
7.2 Balance or Weighing Scale—An analytical balance or
Fig. 1 has a pressure vessel volume of approximately 0.011 m
weighing scale is required that is capable of measuring the
[671 in. ]. The burst valve consists of a pair of thin biaxially
mass of the projectile accurately to within 60.5 %.
oriented polyethylene terephthalate (BoPET) polyester sheets
7.3 Velocity Measurement—The impact device shall be
with a thickness of approximately 0.125 mm [0.005 in.] with a
instrumented to measure the velocity of the impactor at a given
nichrome wire sandwiched between them in a circular shape
point before impact. Several approaches to velocity measure-
slightly smaller in diameter than the gun barrel. The gun barrel
ment are available, and the selection of a particular method is
has a length of approximately 3.7 m [12 ft] and a machined-
dependent upon the desired measurement accuracy. One com-
smooth bore with a diameter approximately 0.05 mm
monly used approach to velocity measurement uses a pair of
[0.002 in.] greater than the diameter of the projectile. To
laser beams pointed in a direction normal to the path of the
operate the device, a projectile is loaded into the breach of the
projectile and separated by a known distance. The laser beams
gun, and the pressure vessel is connected to the gun barrel with
are directed at detectors that measure the light intensity.As the
the polyester sandwiched between the two. Helium or nitrogen
projectile interrupts the laser beam, the detector signal changes
is introduced into the pressure vessel to the desired pressure.A
state, indicating an interruption in the light path. The time
voltage is applied to the nichrome wire, which heats up and
between the detections and the distance between the beams are
causes the polyester sheets to rupture. The released gas
used to calculate the projectile velocity. An alternate approach
accelerates the projectile down the gun barrel. Before impact,
is to use photogrammetry to track targets on the projectile to
and after exiting the gun barrel, there is a region of free flight,
compute velocity. The required accuracy of the velocity
which shall be long enough for the velocity and the orientation
measurement system, and the associated method for verifying
of the projectile to be measured.
the measurement accuracy, shall be specified by the test
7.7 Support Fixture—The impact test fixture, shown sche-
requestor.
matically in Fig. 2, is constructed from structural steel,
NOTE 1—It is recommended that the test requestor specify the required
Specification A36/A36M or equivalent or higher strength, and
accuracy of the velocity measurement as a percentage of indicated value.
consists of a heavy back frame with a circular aperture and a
7.4 Attitude Measurement—Equipment shall be used for
circular front frame with through bolts that thread into nuts on
measuring the orientation of the projectile just before impact.
the back of the frame. The inner diameter of the front frame
The accuracy of data shall be reported. An example of
and the circular aperture of the back frame is 254 mm [10 in.].
equipment that may be used is a pair of calibrated high-speed
The test specimen is sandwiched between the two components.
cameras and a digital image correlation system. The required
The test specimen shall extend a minimum of 25.4 mm [1 in.]
accuracy of the orientation measurement system, and the
beyond the circular aperture of the back frame so that it is
associated method for verifying the measurement accuracy,
completely clamped between the two parts of the fixture. The
shall be specified by the test requestor.
specimen contains machined holes to accommodate the
through bolts. To minimize slippage at the specimen
7.5 Impact Location Measurement—Tools shall be used for
boundaries, the bolts are precision shoulder type with a
measuringtheimpactlocationrelativetothecenterpointofthe
specimen.The accuracy of the equipment shall be reported.An
exampleofequipmentthatmaybeusedisastandardmachinist
scale.
7.6 In general, any device capable of accelerating the
projectile in free flight into the test specimen with a repeatable
velocity and orientation at sufficient speeds to penetrate the
panel is acceptable. The device should be designed in such a
way to minimize axial spin in the projectile.Aschematic of an
example of such a device is shown in Fig. 1. This device is a
single-stage compressed gas gun and consists of a pressure
FIG. 1 Schematic of a Gas Gun Used for Accelerating Projectiles FIG. 2 Exploded View of Impact Test Fixture, Including Front
into Composite Panels Frame, Test Panel, Back Frame, and Clamping Bolts
D8101/D8101M − 18
minimum tensile strength of 965 MPa [140 ksi]. The holes in application, the thickness of the front face can be varied. This
the front frame and the specimen are precision machined to shall be done without changing the front face inner or outer
accommodate a clearance fit. All bolts should be torqued to a radii. However, results are invalidated if the front face thick-
minimum value of 25 N-m [220 in.-lb]. Number the bolts ness is reduced to the point at which the impact test results in
sequentially from 1 to 28 around the bolt circle. Using a torque visible permanent deformation of the projectile. The mass of
wrench,tightenthenutoneachstudinanappropriatesequence th
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D8101/D8101M − 17 D8101/D8101M − 18
Standard Test Method for
Measuring the Penetration Resistance of Composite
Materials to Impact by a Blunt Projectile
This standard is issued under the fixed designation D8101/D8101M; 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.
1. Scope
1.1 This test method measures the resistance of flat composite panels in one specific clamping configuration to penetration by
a blunt projectile in free flight. In this test method, the term “penetration” is defined as the case in which the projectile travels
completely through the composite panel and fully exits the back side. The composite materials may be continuous fiber angle-ply,
woven or braided fiber-reinforced polymer matrix composites, or chopped fiber-reinforced composites. The resistance to
penetration is quantified by a statistical function that defines the probability of penetration for a given kinetic energy.
1.2 This test method is intended for composite test panels in which the thickness dimension is small compared with the test
panel width and length (span to thickness greater than fifty). on the order of 40 or greater).
1.3 This test method is intended for applications such as jet engine fan containment, open rotor engine blade containment, or
other applications in which protection is needed for projectiles at velocities typically lower than seen in ballistic armor applications.
The typical impact velocity that this test is intended for is in the range of 100 to 500 m/s [300 to 1500 ft/s], as opposed to higher
velocities associated with armor penetration.
1.4 A flat composite panel is fixed between a circular-shaped clamping fixture and a large base fixture each with a large coaxial
hole defining a region of the panel that is subjected to impact in the direction normal to the plane of the flat panel by a blunt
projectile. Clamping pressure is provided by twenty-eight28 through bolts that pass through the front clamp, the test specimen, and
the back plate. The mass, geometry, desired impact kinetic energy, and impact orientation of the projectile with respect to the panel
are specified before the test. Equipment and procedures are required for measuring the actual impact velocity and orientation during
the test. The impact penetration resistance can be quantified by either the velocity or kinetic energy required for the projectile to
penetrate the test panel fully. A number of tests are required to obtain a statistical probability of penetration for given impact
conditions.
1.5 This test method measures the penetration resistance for a specific projectile and test configuration and can be used to screen
materials for impact penetration resistance, compare the impact penetration resistance of different composite materials under the
same test geometry conditions, or assess the effects of in-service or environmental exposure on the impact penetration resistance
of materials.
1.6 The impact penetration resistance is highly dependent on the test panel materials and architecture, projectile geometry and
mass, and panel boundary conditions. Results are not generally scalable to other configurations but, for the same test
configurations, may be used to assess the relative impact penetration resistance of different materials and fiber architectures.
1.7 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated
in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values
from the two systems may result in nonconformance with the standard. Within the text, the inch-pound units are shown in brackets.
1.8 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.9 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.
This test method is under the jurisdiction of ASTM Committee D30 on Composite Materials and is the direct responsibility of Subcommittee D30.05 on Structural Test
Methods.
Current edition approved April 1, 2017Oct. 15, 2018. Published April 2017February 2019. DOI: 10.1520/D8101_D8101M-17.Originally approved in 2017. Last previous
edition approved in 2017 as D8101/D8101M – 17. DOI: 10.1520/D8101_D8101M-18.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D8101/D8101M − 18
2. Referenced Documents
2.1 ASTM Standards:
A36/A36M Specification for Carbon Structural Steel
D792 Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement
D883 Terminology Relating to Plastics
D3171 Test Methods for Constituent Content of Composite Materials
D3878 Terminology for Composite Materials
D5229/D5229M Test Method for Moisture Absorption Properties and Equilibrium Conditioning of Polymer Matrix Composite
Materials
D5687/D5687M Guide for Preparation of Flat Composite Panels with Processing Guidelines for Specimen Preparation
E2533 Guide for Nondestructive Testing of Polymer Matrix Composites Used in Aerospace Applications
2.2 NIJ StandardStandard:
NIJ Standard 0101.06 Body Amor—Ballistic Resistance
3. Terminology
3.1 Definitions—In Terminology D3878, terms are defined relating to composite materials. In Terminology D883, terms are
defined related to plastics. In the event of a conflict between terms, Terminology D3878 shall have precedence over the other
standards.
3.2 Definitions of Terms Specific to This Standard: If the term represents a physical quantity, its analytical dimensions are stated
immediately following the term (or letter symbol) in fundamental dimension form, using the following ASTM standard symbology
for fundamental dimensions, shown within square brackets: [M] for mass, [L] for length, [T] for time, [θ] for thermodynamic
temperature, and [nd] for non-dimensional quantities. Use of these symbols is restricted to analytical dimensions when used with
square brackets, as the terms may have other definitions when used without the brackets.
-1
3.2.1 impact velocity, Vi [LT ], n—velocity of the projectile in the direction of projectile travel just before impact.
3.2.2 penetrate, v—to travel fully through a body and emerge completely on the other side.
3.2.3 projectile face, n—front portion of the projectile that first comes into contact with the test panel.
3.2.4 projectile orientation, n—angular position of the projectile as determined by a set of measurements relative to the
reference coordinate system.
3.2.4.1 Discussion—
Typically used to define the angular position of the projectile just before impact with the test specimen.
3.2.5 Impact Penetration Resistance (IPR), n—the kinetic energy (or associated impact velocity) of a projectile corresponding
to the 50%50 % probability of penetration.
3.2.6 reference coordinate system, n—coordinate system defined for the purpose of identifying the impact velocity and
orientation of the projectile and the orientation of the test specimen.
3.2.6.1 Discussion—
An example of a reference coordinate system is one in which the X direction is normal to the plane of the flat panel with positive
values measured in the direction of the projectile travel, the Y direction is in the plane of the flat test panel and is horizontal with
positive values measured to the right when viewing the panel from the impacted side, and the Z direction is vertical with positive
values measured downward and the origin is at the center of the panel on the impacted face. The reference coordinate system is
defined by the organization conducting the tests.
-1
3.2.7 residual velocity, Vr [LT ], n—absolute velocity of the projectile just after penetration (if penetration occurs).
3.3 Symbols:
2 -2
3.3.1 E [ML T ] —Loss in kinetic energy of the projectile as a result of the impact.
a
2 -2
3.3.2 E [ML T ] —Kinetic energy of the projectile at the time of impact.
i
2 -2
3.3.3 E [ML T ]—Kinetic energy of the projectile after penetrating the test panel (if penetration occurs).
r
3.3.4 M[M]—Projectile mass.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from the National Institute of Justice, Washington, DC, www.jij.gov/publications.www.nij.gov/publications.
D8101/D8101M − 18
4. Summary of Test Method
4.1 An impact test is performed by accelerating a defined projectile to a specified velocity, typically with the use of a
single-stage gas gun, into a composite test panel that is supported in a fixture. The test panel is supported in a circular fixture with
precision bolts extending through a front clamp and the specimen itself to avoid slipping of the specimen at the boundaries. The
location of the holes is remote from the impact site so that damage is not initiated at the holes. Depending on the kinetic energy
of the projectile, it may or may not damage or penetrate the test panel. The penetration resistance is quantified by either the velocity
or kinetic energy required to penetrate the test panel. The penetration resistance is a function of the geometry and materials of the
test panel. Comparisons between materials or material conditions cannot be made unless identical test configurations and test
conditions are used.
4.2 Procedures and equipment for measuring the impact velocity and orientation of the projectile just before impact are required.
Equipment for measuring the residual velocity of the projectile after penetration, if it occurs, is desirable but not required.
5. Significance and Use
5.1 Advanced composite systems are used in a number of applications as shields to prevent penetration by projectiles. In
general, the use of composites is more effective for blunt, rather than sharp, projectiles or in hybrid systems in which an additional
shield can be used to blunt a sharp projectile. Knowledge of the penetration impact resistance of different material systems or the
effects of environmental or in-service load exposure to the penetration resistance of given materials is useful for product
development and material selection.
5.2 An impact test used to measure the penetration resistance of a material can serve the following purposes:
5.2.1 To quantify the effect of fiber architecture, stacking sequence, fiber and matrix material selection, and processing
parameters on the penetration resistance of different composite materials;
5.2.2 To measure the effects of environmental or in-service load exposure on the penetration impact resistance of a given
material system; and
5.2.3 As a tool for quality assurance requirements for materials designed for penetration resistance applications.
5.3 The penetration resistance values obtained with this test method are most commonly used in material specification and
selection and research and development activities. The data are not intended for use in establishing design allowables, as the results
are specific to the geometry and physical conditions tested and are not generally scalable to other configurations.
5.4 The reporting section requires items that tend to influence the penetration resistance of material systems. These include the
following: fiber and matrix materials, fiber architecture, layup sequence, methods of material fabrication, environmental exposure
parameters, specimen geometry and overall thickness, void content, specimen conditioning, testing environment and exposure
time, specimen fixture and alignment, projectile mass and geometry, and projectile orientation at impact. Additional reporting
requirements include size and description of damage, results of any pre- and post-test nondestructive inspection, impact velocity,
accuracy of the velocity measurement apparatus, and whether or not the projectile penetrated the panel. Residual velocity is a
desirable, but not a necessary, value to be reported.
5.5 The reporting section shall also include the parameters of a statistical function that gives the probability of penetration as
a function of impact kinetic energy (see 14.4).
5.6 The relevant measurements that result from the impact test are the kinetic energy and impact velocity of the projectile and
whether or not the projectile penetrated the specimen. An optional item to be measured is the loss in kinetic energy of the projectile
as a function of impact velocity if measurements of the residual velocity are recorded.
6. Interferences
6.1 The impact penetration resistance is dependent on many factors, such as test specimen thickness, areal density, fiber
architecture, fiber and matrix materials, fiber volume ratio, pre-test environmental and load exposure, test environment, boundary
conditions, projectile geometry, and projectile mass. Consequently, comparisons cannot be made between materials unless identical
test configurations, test conditions, and material thickness are used. Therefore, all deviations from the standard test configuration
shall be reported in the results.
6.2 Materials and Specimen Preparation—Poor material fabrication practices, lack of control of fiber placement and stacking
sequence alignment, and damage induced by improper specimen machining are known causes of high material data scatter in
composites in general. Important aspects of panel specimen preparation that contribute to data scatter include thickness variation
and out-of-plane curvature.
6.3 Impact Location and Projectile Orientation—The location of the projectile impact shall occur at the center of the panel for
results to be valid. Lack of control over the impact location will produce scatter in the results and invalidate comparisons between
different materials or environmental exposure conditions. The orientation of the projectile shall be such that its center of mass is
aligned with the impact direction and the impact direction is normal to the plane of the test specimen. Differences in projectile
orientation between tests will lead to data scatter.
D8101/D8101M − 18
6.4 Support Fixture Characteristics—Results are affected by the dimensions, as well as the corresponding mass and rigidity of
the support fixture. Bolt torque differences will affect the boundary conditions and lead to inconsistent results. The support fixture
shall be significantly more rigid than the test specimen for results to be valid.
6.5 Impact Device Characteristics—The method of accelerating the projectile will affect the repeatability of the projectile
impact velocity and orientation. Lack of control over repeatability will require a greater number of tests to ensure statistically valid
results are obtained.
6.6 Velocity and Orientation Measurement Equipment—Valid results are directly dependent on the accuracy of the velocity and
orientation measurements.
6.7 Damage Modes—Damage mode differences between materials will affect the evaluation of results. Widespread damage that
extends to the specimen boundaries may invalidate results.
6.8 Nondestructive Inspection—Nondestructive testing (NDT) results are affected by a number of factors, including the
particular Practice or Test Method used, the inherent variability of the NDT Practice or Test Method, and the experience of the
operator.
7. Apparatus
7.1 Micrometers and Calipers—A micrometer with a 4 to 7 mm [0.16 to 0.28 in.] nominal diameter ball interface or a flat anvil
interface shall be used to measure the specimen thickness. A ball interface is recommended for thickness measurements when at
least one surface is irregular (for example, a coarse peel ply surface that is neither smooth nor flat). A micrometer or caliper with
a flat anvil interface shall be used for measuring length, width, and other machined surface dimensions. The use of alternative
measurement devices is permitted if specified (or agreed to) by the test requestor and reported by the testing laboratory. The
accuracy of the instrument(s) shall be suitable for reading to within 1 % 1 % of the specimen dimensions. For typical specimen
geometries, an instrument with an accuracy of 60.0025 mm [60.0001 in.] is adequate for thickness measurements, while an
instrument with an accuracy of 60.025 mm [60.001 in.] is adequate for measurement of length, width, and other machined surface
dimensions.
7.2 Balance or Weighing Scale—An analytical balance or weighing scale is required that is capable of measuring the mass of
the projectile accurately to within 60.5 %.
7.3 Velocity Measurement—The impact device shall be instrumented to measure the velocity of the impactor at a given point
before impact. Several approaches to velocity measurement are available, and the selection of a particular method is dependent
upon the desired measurement accuracy. One commonly used approach to velocity measurement uses a pair of laser beams pointed
in a direction normal to the path of the projectile and separated by a known distance. The laser beams are directed at detectors that
measure the light intensity. As the projectile interrupts the laser beam, the detector signal changes state, indicating an interruption
in the light path. The time between the detections and the distance between the beams are used to calculate the projectile velocity.
An alternate approach is to use photogrammetry to track targets on the projectile to compute velocity. The required accuracy of
the velocity measurement system, and the associated method for verifying the measurement accuracy, shall be specified by the test
requestor.
NOTE 1—It is recommended that the test requestor specify the required accuracy of the velocity measurement as a percentage of indicated value.
7.4 Attitude Measurement—Equipment shall be used for measuring the orientation of the projectile just before impact. The
accuracy of data shall be reported. An example of equipment that may be used is a pair of calibrated high-speed cameras and a
digital image correlation system. The required accuracy of the orientation measurement system, and the associated method for
verifying the measurement accuracy, shall be specified by the test requestor.
7.5 Impact Location Measurement—Impact Location Measurement—Tools Tools shall be used for measuring the impact
location relative to the center point of the specimen. The accuracy of the equipment shall be reported. An example of equipment
that may be used is a standard machinist scale.
7.6 In general, any device capable of accelerating the projectile in free flight into the test specimen with a repeatable velocity
and orientation at sufficient speeds to penetrate the panel is acceptable. The device should be designed in such a way to minimize
axial spin in the projectile. A schematic of an example of such a device is shown in Fig. 1. This device is a single-stage compressed
gas gun and consists of a pressure vessel, a burst valve, and a gun barrel aimed at the test specimen. For safety, the test specimen
should be located inside of a closed containment structure vented to allow pressure in the structure to be released. The device
3 3
shown in Fig. 1 has a pressure vessel volume of approximately 0.011 m0.011 m [671 in. ]. The burst valve consists of a pair of
thin biaxially oriented polyethylene terephthalate (BoPET) polyester sheets with a thickness of approximately 0.125 mm [0.005
in.] 0.125 mm [0.005 in.] with a nichrome wire sandwiched between them in a circular shape slightly smaller in diameter than the
gun barrel. The gun barrel has a length of approximately 3.7 m [12 ft] 3.7 m [12 ft] and a machined-smooth bore with a diameter
approximately 0.05 mm [0.002 in.] 0.05 mm [0.002 in.] greater than the diameter of the projectile. To operate the device, a
projectile is loaded into the breach of the gun, and the pressure vessel is connected to the gun barrel with the polyester sandwiched
between the two. Helium or nitrogen is introduced into the pressure vessel to the desired pressure. A voltage is applied to the
D8101/D8101M − 18
FIG. 1 Schematic of a Gas Gun Used for Accelerating Projectiles into Composite Panels
nichrome wire, which heats up and causes the polyester sheets to rupture. The released gas accelerates the projectile down the gun
barrel. Before impact, and after exiting the gun barrel, there is a region of free flight, which shall be long enough for the velocity
and the orientation of the projectile to be measured.
7.7 Support Fixture—The impact test fixture, shown schematically in Fig. 2, is constructed from structural steel, Specification
A36/A36M or equivalent or higher strength, and consists of a heavy back frame with a circular aperture and a circular front frame
with through bolts that thread into nuts on the back of the frame. The inner diameter of the front frame and the circular aperture
of the back frame is 254 mm [10 in.]. The test specimen is sandwiched between the two components. The test specimen shall
extend a minimum of 25.4 mm [1 in.] beyond the circular aperture of the back frame so that it is completely clamped between
the two parts of the fixture. The specimen contains machined holes to accommodate the through bolts. To minimize slippage at
the specimen boundaries, the bolts are precision shoulder type with a minimum tensile strength of 965 MPa [140 ksi]. The holes
in the front frame and the specimen are precision machined to accommodate a clearance fit. All bolts should be torqued to a
minimum value of 25 N-m [220 in.-lb]. Number the bolts sequentially from 1 to 28 around the bolt circle. Using a torque wrench,
tighten the nut on each stud in an appropriate sequence to distribute the pressure on the test panel. A recommended order for
tightening the bolts is 1, 15, 8, 22, 5, 19, 12, 26, 3, 17, 10, 24, 6, 20, 13, 27, 2, 16, 9, 23, 7, 21, 14, 28, 4, 18, 11, and 25. Tighten
the bolts according to the following increments:
7.7.1 Tighten each stud to approximately 40 % of the final torque,
7.7.2 Tighten each stud to approximately 70 % of the final torque, and
7.7.3 Tighten each stud to 100 % of the final torque.
7.7.4 Support Fixture Details—Detailed drawings fo
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