Testing of Body
Armor Materials
Phase III
Committee on Testing of Body Armor Materials for Use by the U.S. Army—Phase III
Board on Army Science and Technology
Division on Engineering and Physical Sciences
and
Committee on National Statistics
Division of Behavioral and Social Sciences and Education
NATIONAL RESEARCH COUNCIL
OF THE NATIONAL ACADEMIES
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This material is based on work supported by the National Science Foundation under Grant No. SES-0453930, Amendment #012. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.
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COMMITTEE ON THE TESTING OF BODY ARMOR FOR THE U.S. ARMY – PHASE III
LARRY G. LEHOWICZ, MG, U.S. Army (retired), Chair, Quantum Research International, Arlington, Virginia
CAMERON R. BASS, Duke University, Durham, North Carolina
THOMAS F. BUDINGER, E.O., NAE/IOM,1 Lawrence Berkeley National Laboratory, Berkeley, California
MORTON M. DENN, NAE, City College of the City University of New York
WILLIAM G. FAHRENHOLTZ, Missouri University of Science and Technology, Rolla
RONALD D. FRICKER, JR., Naval Postgraduate School, Monterey, California
YOGENDRA M. GUPTA, Washington State University, Pullman
DENNIS K. KILLINGER, University of South Florida, Tampa
VLADIMIR B. MARKOV, Advanced Systems and Technologies, Inc., Irvine, California
JAMES D. McGUFFIN-CAWLEY, Case Western Reserve University, Cleveland, Ohio
RUSSELL N. PRATHER, Survice Engineering Company, Bel Air, Maryland
SHELDON WIEDERHORN, NAE, National Institute of Standards and Technology, Gaithersburg, Maryland
ALYSON GABBARD WILSON, Institute for Defense Analyses, Alexandria, Virginia
Staff
BRUCE A. BRAUN, Director, Board on Army Science and Technology
ROBERT LOVE, Study Director
HARRISON T. PANNELLA, Senior Program Officer
NIA D. JOHNSON, Senior Research Associate, Board on Army Science and Technology
JAMES MYSKA, Senior Research Associate, Board on Army Science and Technology
DEANNA P. SPARGER, Program Administrative Coordinator, Board on Army Science and Technology
ANN LARROW, Research Assistant
JOSEPH PALMER, Senior Program Assistant
ALICE WILLIAMS, Senior Program Assistant (until September 10, 2010)
CONSTANCE CITRO, Director, Committee on National Statistics
DENNIS CHAMOT, Acting Director, National Materials Advisory Board
JAMES P. McGEE, Director, Laboratory Assessments Board
________________________
1NAE/IOM, National Academy of Engineering/Institute of Medicine.
BOARD ON ARMY SCIENCE AND TECHNOLOGY
ALAN H. EPSTEIN, Chair, Pratt & Whitney, East Hartford, Connecticut
DAVID M. MADDOX, Vice Chair, Independent Consultant, Arlington, Virginia
DUANE ADAMS, Independent Consultant, Arlington, Virginia
ILESANMI ADESIDA, University of Illinois at Urbana-Champaign
MARY E. BOYCE, Massachusetts Institute of Technology, Cambridge
EDWARD C. BRADY, Strategic Perspectives, Inc., Fort Lauderdale, Florida
W. PETER CHERRY, Independent Consultant, Ann Arbor, Michigan
EARL H. DOWELL, Duke University, Durham, North Carolina
JULIA D. ERDLEY, Pennsylvania State University, State College
LESTER A. FOSTER, Electronic Warfare Associates, Herndon, Virginia
JAMES A. FREEBERSYSER, BBN Technology, St. Louis Park, Minnesota
RONALD P. FUCHS, Independent Consultant, Seattle, Washington
W. HARVEY GRAY, Independent Consultant, Oak Ridge, Tennessee
JOHN J. HAMMOND, Independent Consultant, Fairfax, Virginia
RANDALL W. HILL, JR., University of Southern California Institute for Creative Technologies, Playa Vista
JOHN W. HUTCHINSON, Harvard University, Cambridge, Massachusetts
MARY JANE IRWIN, Pennsylvania State University, University Park
ROBIN L. KEESEE, Independent Consultant, Fairfax, Virginia
ELLIOT D. KIEFF, Channing Laboratory, Harvard University, Boston, Massachusetts
WILLIAM L. MELVIN, Georgia Tech Research Institute, Smyrna
ROBIN MURPHY, Texas A&M University, College Station
SCOTT PARAZYNSKI, University of Texas Medical Branch, Galveston
RICHARD R. PAUL, Independent Consultant, Bellevue, Washington
JEAN D. REED, Independent Consultant, Arlington, Virginia
LEON E. SALOMON, Independent Consultant, Gulfport, Florida
JONATHAN M. SMITH, University of Pennsylvania, Philadelphia
MARK J.T. SMITH, Purdue University, West Lafayette, Indiana
MICHAEL A. STROSCIO, University of Illinois, Chicago
DAVID A. TIRRELL, California Institute of Technology, Pasadena
JOSEPH YAKOVAC, JVM LLC, Hampton, Virginia
Staff
BRUCE A. BRAUN, Director
CHRIS JONES, Financial Manager
DEANNA P. SPARGER, Program Administrative Coordinator
COMMITTEE ON NATIONAL STATISTICS
LAWRENCE D. BROWN, Chair, Department of Statistics, Wharton School, University of Pennsylvania
JOHN M. ABOWD, School of Industrial and Labor Relations, Cornell University
DAVID CARD, Department of Economics, University of California, Berkeley
ALICIA CARRIQUIRY, Department of Statistics, Iowa State University
CONSTANTINE GATSONIS, Center for Statistical Sciences, Brown University
JAMES S. HOUSE, Survey Research Center, Institute for Social Research, University of Michigan
MICHAEL HOUT, Survey Research Center, University of California, Berkeley
SALLIE ANN KELLER, University of Waterloo, Ontario, Canada
LISA LYNCH, Heller School for Social Policy and Management, Brandeis University
SALLY C. MORTON, Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh
RUTH D. PETERSON, Criminal Justice Research Center, Ohio State University
EDWARD H. SHORTLIFFE, Columbia University and Arizona State University
HAL STERN, Donald Bren School of Information and Computer Sciences, University of California, Irvine
JOHN H. THOMPSON, National Opinion Research Center, University of Chicago
ROGER TOURANGEAU, Westat, Rockville, Maryland
Staff
CONSTANCE CITRO, Senior Board Director
JULIA KISA SHAKEER, Financial Associate
JACQUI SOVDE, Program Associate
Preface
This report is the final volume of a three-phase study commissioned by the Director of Operational Test and Evaluation (DOT&E) of the Department of Defense (DoD) to assist in addressing shortcomings that had been reported by the Government Accountability Office (GAO) and the DoD Inspector General in DoD’s body armor testing process. Independent committees were empanelled for the three study phases. Each committee produced an independent report, although this final Phase III report builds on the results of the letter reports delivered in Phases I and II, both of which provided findings and recommendations on key issues that required near-term resolution by DOT&E. The study was conducted under the auspices of the National Research Council (NRC) Board on Army Science and Technology (BAST) and Committee on National Statistics.
The Phase I letter report, released in January 2010, addressed the adequacy of laser instrumentation for evaluating ballistics tests in clay material. The Phase II report, released in May 2010, focused on the behavior of ballistics clay used as a recording medium during live-fire testing. The Phase III committee had more time for meetings and data gathering than the two previous committees and was able to use the substantial amount of data collected throughout the entire study. As a result the committee was able to delve more deeply into all available data than had been possible in the earlier phases of the effort.
This Phase III report provides a wide range of recommendations designed to help enable the entire body armor community to utilize an effective testing process leading to fielding the best equipment possible that meets performance specifications while reducing the weight burden placed on soldiers in training or combat.
The Phase III committee deserves special thanks for its hard work. Several committee members went well beyond the norm in interviewing numerous experts, assessing the pertinent issues, and developing recommendations to address the many demands of the committee’s statement of task. In particular, committee member Thomas Budinger deserves special credit for leading the Phase III ad hoc instrumentation committee subgroup that produced a thoughtful review of the data and information related to instrumentation. The committee is also grateful to the many DoD, Army, Marine Corps, industry, and contractor personnel engaged in body armor testing for the useful information they provided.
Finally, the committee also greatly appreciates the support and assistance of the NRC staff members who assisted the committee in its fact-finding activities and in the production of the three separate committee reports. In particular, thanks are due to the BAST staff, principally Bruce Braun, Margaret Novack, and Robert Love, who ably facilitated the committee’s work.
Larry Lehowicz, Chair
Committee on Testing of Body Armor
Materials for Use by the U.S. Army—Phase
III
Acknowledgment of Reviewers
This report has been reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise, in accordance with procedures approved by the National Research Council’s Report Review Committee. The purpose of this independent review is to provide candid and critical comments that will assist the institution in making its published report as sound as possible and to ensure that the report meets institutional standards for objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process. We wish to thank the following individuals for their review of this report:
Morris E. Fine (NAE), Northwestern University
John S. Foster, Jr. (NAE), GKN Aerospace Transparency Systems
David Higdon, Los Alamos National Laboratory
Peter Matic, Naval Research Laboratory
Erik Novak, Veeco Instruments,
Henry Smith (NAE), Massachusetts Institute of Technology
Leslie J. Struble, University of Illinois
Stephen F. Vatner, New Jersey Medical School
Emmanuel Yashchin, IBM Watson Research Center
Laurence R. Young (NAE/IOM), Massachusetts Institute of Technology
Although the reviewers listed above have provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations, nor did they see the final draft of the report before its release. The review of this report was overseen by Lawrence D. Brown, NAS, Wharton School, University of Pennsylvania, and Arthur H. Heuer, NAE, Case Western Reserve University. Appointed by the National Research Council, they were responsible for making certain that an independent examination of this report was carried out in accordance with institutional procedures and that all review comments were carefully considered. Responsibility for the final content of this report rests entirely with the authoring committee and the institution.
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Contents
Fiber and Resin Composites in Helmets
Medical Study Basis for Testing Body Armor
Government Accountability Office Report
3 HISTORICAL BASIS FOR CURRENT BODY ARMOR TESTING
Rifle Threats for Hard Body Armors
Work Performed after the Prather Study
Use of Backing Material as a Recording Medium
Characteristics and Properties of RP #1
Influence of Structure on Properties of Oil-Base Modeling Clay
Short-Term Development of an Interim Standard Clay Formulation for Ballistic Testing
Medium-Term and Long-Term Replacements for Modeling Clay
Roadmap for Improving the Testing Process
5 INSTRUMENTATION AND PROCEDURES FOR MEASURING AN INDENT IN A CLAY BACKING MATERIAL
Conceptual Steps Toward Improvements in the Measurement of BFD
Instrumentation Performance Based on Statistical Analysis
Overview of Current Instrumentation and Measurements
Compensating for Offset between the Point of Aim and the Deepest Indent
Variability (Noise) in the Overall Testing Process
Need for a Stand-Alone BFD Artifact or Standard Model for Interorganization Verification
Characteristics of a “Best Utility” Measuring Instrument
6 STATISTICAL CONSIDERATIONS IN BODY ARMOR TESTING
Statistically Principled Testing
Uncertainty and Variation Drive Overdesign
Key Test Protocol Design Requirements
Historical First Article Testing Protocols
DOT&E Protocol for Body Armor FAT
Ballistic Helmet Test Methodolgies
Existing Human Injury Criteria
Head Injury from Ballistic Impact
Helmet Design and Suspension Systems
Existing Helmet Test Methodologies
H.P. White Laboratory Test Procedure
8 MEDICAL BASIS FOR FUTURE BODY ARMOR TESTING
Thoracic Ballistic Test Methodologies
Introduction to Behind Armor Blunt Trauma
Injury Criteria and Experimentation
Blast Injury Criteria and Blastlike Mechanisms
Low-Rate Blunt Trauma Mechanisms
Human Epidemiology for Battlefield BABT
Current Epidemiology for Battlefield/Law Enforcement BABT
Large Animal Experiments for Behind-Armor Blunt Trauma
Potential Adverse Effects of Body Armor in Blast Exposures
Cadaveric Experiments for Behind-Armor Blunt Trauma
Rationale for Large-Animal, Live-Fire Experiments
Instrumented Determination of Backface Deformation—Research Directions
Instrumented Response Elements
Instrumented Detailed Anatomical Surrogates
9 FUTURE IMPROVEMENTS IN TESTING METHODOLOGY
Synopsis of Near-Term Improvements
Linking Medical Research Data to Product Testing Criteria
Dynamics and Measurement of Behind-Armor Forces
Synchronizing the Stakeholders
Military and Law Enforcement Personnel
Testers—Developmental and Operational
Establishing National Standards
A Biographical Sketches of Committee Members
D Report Sections Cross-Referenced to the Statement of Task
E Ballistic Body Armor Insert Composition and Defeat Mechanisms
F Committee Responses to the Government Accountability Office Report
G Determining the Necessary Level of Precision for Body Armor Testing
H Statistical Tolerance Bounds
I Analytical Approaches for Comparing Test Protocols
J Contemporary Methods for Assessing Behind-Armor Blunt Trauma in Live Animals
M Estimating the Accuracy and Precision of the Digital Caliper and Faro Laser
Tables, Figures, and Boxes
TABLES
3-1 Strengths and Weaknesses of the Prather Methodology
4-1 Elastic Recovery in Modified Charpy Testing of Oil-Based Modeling Clay
6-4 Risk Comparisons for Probability of Complete Penetration
7-1 Characteristics of Test Rounds from NIJ Standard-0106.01
7-2 H.P. White Laboratory Test Procedure
8-1 Muzzle Parameters for Various Types of Rounds
8-2 Energy/Momentum for Various Typical Thoracic Trauma Situations
8-3 Description of Levels of Thoracic Trauma
8-4 Combat Effectiveness vs. Levels of Thoracic Trauma
8-5 Bullet Specifications and Injury Outcome
9-1 Strengths and Weaknesses of the Prather Methodology
FIGURES
2-1 The clay appliqué applied to the clay box
2-2 Surface of the BFD as measured by a laser scanning system
3-4 Logistic regression model of death vs. deformation for blunt impact into goat chests
3-6 Clay deformation behind hard armor with rifle round threats
4-1 A schematic illustration of the stress-strain curves for two idealized solids
4-3 Column drop test as performed at ATC
4-8 A clay box used for .32-cal rubber sting ball testing
4-10 A schematic illustration of the “thixotropic cycle” of a two-phase system
4-11 Optical micrographs of a three-dimensional network of spherical latex particles
5-1 Digital calipers used in armor testing
6-5 Plot of the manufacturer’s risk for various Pr(nP) under the DOT&E protocol
7-2 Ballistic impact injury timescales
7-3 Likeness of a deformed personnel armor system for ground troops helmet
7-4 Cadaver instrumentation overview
7-6 Residual head/neck velocity from momentum transfer to the helmet/head system
7-7 Impact energy for helmet standards
7-8 Ballistic (high-rate) skull fracture data vs. impact injury criteria for typical blunt injury
7-9 NIJ sagittal penetration head form
7-12 Head form clay conditioning by analogy
7-16 Peepsite head forms: different head forms for different shot directions
7-17 Left, UVA head form; right, risk assessment
7-19 Arrangement and dimensions of load cells in the BLS head form
8-1 Initial energy and momentum for ballistics and other blunt impacts
8-7 Threshold damage for various tissues
8-8 ASII values versus peak inward chest wall velocity
8-9 Overpressure/duration blast injury criteria
8-10 Kinetic energy vs. injury severity
8-11 Time of delivery of wounded to the CMH (average 1983-1984)
8-12 Severity of wounds for patients delivered to the CMH (average 1983-1984)
8-13 Lateral dog thorax impacted by nonpenetrating missiles
8-14 Impact energy (scaled to a 75 kg man) vs. increased lung mass
8-15 Body armor for Oksbøl trials
8-16 Average first and second peak pressure, Oksbøl trials
8-17 Average postmortem lung mass, Oksbøl trials
8-18 Oksbøl first peak on Bowen curve
8-19 Animal fatalities during monitoring period
8-22 Relationship between area of lung surface contusion and pressure 6 cm from point of impact
8-23 Examples of BABT assessment devices and methodologies
8-24 DERA BABT simulator displacement sensor system
8-25 DERA tissue viscoelastic stimulant concept as described by Mirzeabassov et al., 2000
8-26 Hybrid III 50th percentile male dummy
8-28 Human CT scan; finite-element model
8-30 AUSMAN thorax with body armor in place, prior to testing
9-4 Schematic of the dynamic measurement method
9-5 Schematic of stakeholder relationships
G-2 The consequence of measurement error on the apparent depths of BFDs
G-3 The relationship between measurement error and the overall variance in armor testing
G-5 Plot of the difference between the two FAT failure curves
G-6 Photograph, laser scan, and cross section of cavity in RP #1 produced by armor testing
G-7 Digital calipers used in armor testing
G-8 Two images of typical BFD cavities in RP #1 produced by the Faro laser scanner
H-1 Ninety-fifth quintile distribution
J-1 Comprehensive protocol for live-animal live-fire tests
M-1 Plot of the paired BFD measurements made by ATC
M-2 Plot of the paired BFD measurements made by Chesapeake Testing
M-3 Absolute value of offsets for caliper measurements from Realistic Clay III
BOXES
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Acronyms and Abbreviations
AIS | abbreviated injury scale |
AP | armor piercing |
AQL | acceptance quality level |
ARDS | adult respiratory distress syndrome |
ARL | U.S. Army Research Laboratory |
ASTM | American Society of Testing and Materials |
ATC | U.S. Army Aberdeen Test Center |
ATD | anthropometric test device |
ATM | anthropomorphic test module |
BABT | behind-armor blunt trauma |
BFD | backface deformation |
BLS | ballistic load sensing |
CMH | central military hospital |
CMM | co-ordinate measuring machine |
DAI | diffuse axonal injury |
DERA | Defense Evaluation and Research Agency |
DGA | Délégation Générale pour L’Armement |
DoD | Department of Defense |
DOT&E | Office of the Director, Operational Test and Evaluation |
DREV | Defense Research Establishment Valcartier |
ECG | electrocardiogram |
ESAPI | enhanced small arms protective insert |
FAT | first article testing |
FMJ | full metal jacket |
GAO | Government Accountability Office |
HIC | head injury criteria |
IG | Inspector General |
ISS | injury severity score |
kPa | kilopascal |
LAT | lot acceptance testing |
LRN | lead round nose |
MPa | megapascal |
NATO | North Atlantic Treaty Organization |
NIJ | National Institute of Justice |
NIST | National Institute of Standards and Technology |
NRC | National Research Council |
PEO-S | U.S. Army Program Executive Office Soldier |
RCC | right circular cylinder |
RP #1 | Roma Plastilina #1 |
TAB | trauma-attenuating backing |
TBI | traumatic brain injury |
TOP | test operating procedure |
UHMWPE | ultra-high molecular weight polyethylene |
USSOCOM | United States Special Operations Command |
UVA | University of Virginia |
XSAPI | X Small Arms Protective Inserts |