BALLISTIC EXPERIMENTS with TITANIUM and ALUMINUM TARGETS April 2001 6
Total Page：16
File Type：pdf, Size：1020Kb
DOT/FAA/AR-01/21 Ballistic Experiments With Office of Aviation Research Titanium and Aluminum Washington, D.C. 20591 Targets April 2001 Final Report This document is available to the U.S. public through the National Technical Information Service (NTIS), Springfield, Virginia 22161. U.S. Department of Transportation Federal Aviation Administration NOTICE This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The United States Government assumes no liability for the contents or use thereof. The United States Government does not endorse products or manufacturers. Trade or manufacturer's names appear herein solely because they are considered essential to the objective of this report. This document does not constitute FAA certification policy. Consult your local FAA aircraft certification office as to its use. This report is available at the Federal Aviation Administration William J. Hughes Technical Center's Full-Text Technical Reports page: actlibrary.tc.faa.gov in Adobe Acrobat portable document format (PDF). Technical Report Documentation Page 1. Report No. 2. Government Accession No. 3. Recipient's Catalog No. DOT/FAA/AR-01/21 4. Title and Subtitle 5. Report Date BALLISTIC EXPERIMENTS WITH TITANIUM AND ALUMINUM TARGETS April 2001 6. Performing Organization Code 7. Author(s) 8. Performing Organization Report No. Raymond P. Gogolowski and Bruce R. Morgan 9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) Lawrence Livermore National Laboratory P.O. Box 808 11. Contract or Grant No. Livermore, CA 94551 DTFA03-97-Z-90007 12. Sponsoring Agency Name and Address 13. Type of Report and Period Covered U.S. Department of Transportation Final Report Federal Aviation Administration Office of Aviation Research 14. Sponsoring Agency Code Washington, DC 20591 ANM-100 and ANE-100 15. Supplementary Notes The Federal Aviation Administration William J. Hughes Technical Center COTR is William C. Emmerling. 16. Abstract This report describes experiments in penetration mechanics on 6Al-4V titanium and 2024-T3 aluminum. This work was accomplished by the Lawrence Livermore National Laboratory (LLNL) at the LLNL Terminal Ballistics Laboratory of the Physics Directorate under an Interagency Agreement between the Federal Aviation Administration (FAA) William J. Hughes Technical Center and the Department of Energy (DOE). The work was accomplished under the FAA’s Aircraft Catastrophic Failure Prevention Program as part of its research into the turbine engine uncontainment event. The object of the experiments was to determine the ballistic speed limit of 6Al-4V alloy titanium and 2024-T3 alloy aluminum and the failure modes of the projectiles and targets. Data was obtained for both materials using various thickness plates of the test materials to simulate aircraft skins and various size and shape 6Al-4V alloy titanium projectiles. The results of this experimental work will be used to help define the type of material failures in material models of the DYNA3D finite element code, which are being developed/validated for evaluating aircraft/engine designs relative to the federal airworthiness standards and for improving mitigation/containment technology. 17. Key Words 18. Distribution Statement Ballistics, Projectile, Plugging (shear failure), Petal failure, Document is available to the public through the National Projectile fineness ratio, Material constants, DYNA3D Technical Information Service (NTIS), Springfield, Virginia 22161. 19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages 22. Price Unclassified Unclassified 23 Form DOT F1700.7 (8-72) Reproduction of completed page authorized TABLE OF CONTENTS Page EXECUTIVE SUMMARY v 1. INTRODUCTION 1 1.1 Objective of Experiments 1 2. EXPERIMENTAL TECHNIQUES AND SPECIMEN CONFIGURATION 1 2.1 Titanium Projectiles and Aluminum Plate Targets 1 2.1.1 Launch and Measurement Techniques 1 2.1.2 Specimen Configuration (Titanium Projectiles and Aluminum Targets) 3 2.2 Titanium Projectiles and Titanium Plate Targets 5 2.2.1 Launch and Measurement Techniques 5 2.2.2 Specimen Configuration (Titanium Projectiles and Titanium Targets) 6 3. TEST RESULTS 7 3.1 Data From Experiments With Titanium Projectiles and Aluminum Plate Targets 7 3.2 Data From Titanium Projectiles and Titanium Plate Target Experiments 12 4. SUMMARY 14 5. REFERENCES 14 6. DEFINITION OF TERMS 15 iii LIST OF ILLUSTRATIONS Figure Page 1 Solenoid Activated Gas Breech 2 2 Gas Breech, Launcher, Chronograph, and Projectile Trap 2 3 Chronographic and Radiographic Hardware 3 4 Full-Scale Projectile Geometry 4 5 Typical (0.150-inch-Thick) Aluminum PlatesFront Face 10 6 Typical (0.150-inch-Thick) Aluminum PlatesRear Face 10 7 Typical Aluminum Plates With Petal FailuresFront Face 11 LIST OF TABLES Table Page 1 The 0.50″ 6Al-4V Titanium Fragment Simulant Projectiles and 0.150″ 2024-T3 Aluminum Plate Targets 7 2 The 0.50″ 6Al-4V Titanium Right Circular Cylinder Projectile (Fineness Ratio 1.0) and 0.150″ 2024-T3 Aluminum Plate Targets 8 3 The 0.50″ 6Al-4V Titanium Fragment Simulant Projectiles and 0.100″ 2024-T3 Aluminum Plate Targets 8 4 The 0.50″ 6Al-4V Titanium Fragment Simulant Projectiles and 0.050″ 2024-T3 Aluminum Plate Targets 9 5 The 0.50″ 6Al-4V Titanium Right Circular Cylinder Projectile (Fineness Ratio 0.2) and 0.050″ 2024-T3 Aluminum Plate Targets 9 6 Summary of Projectile Ballistic Limit Speeds and Target Failure Modes Aluminum Target 11 7 The 0.58″ 6Al-4V Titanium Projectiles and 6Al-4V Titanium Plate Targets 13 8 Summary of Projectile Ballistic Limit Speeds and Target Failure Modes 13 iv EXECUTIVE SUMMARY This report describes experiments in penetration mechanics on 6Al-4V titanium and 2024-T3 aluminum. The object of the experiments was to determine the ballistic speed limit of 6Al-4V alloy titanium and 2024-T3 alloy aluminum and the failure modes of the projectiles and targets. Data was obtained for both materials using various thickness plates of the test materials to simulate aircraft skins and various size and shape 6Al-4V alloy titanium projectiles. The results of the experimental work will be used to help define the type of material failures in material models of the DYNA3D finite element code, which are being developed and validated for evaluating aircraft and engine designs relative to the federal airworthiness standards and for improving mitigation and containment technology. v/vi 1. INTRODUCTION. 1.1 OBJECTIVE OF EXPERIMENTS. Experiments were run to provide ballistic threshold data for materials used by the aircraft industry using controlled geometries, controlled impact conditions, and characterized materials with well-defined material properties. It was also necessary to be able to examine the targets after impact to assess the failure characteristics. There was no existing data where all these criteria were met. The ballistic data from the experiments is essential in determining failure parameters in the material models. Two sets of fundamental experiments in penetration mechanics were conducted in the Lawrence Livermore National Laboratory (LLNL) Terminal Ballistics Laboratory of the Physics Directorate. The first set of full-scale experiments was conducted with a 14.5-mm air propelled launcher. The objective of the experiments was to determine the ballistic limit speed of 6Al-4V alloy titanium, low fineness ratio projectiles centrally impacting 2024-T3 alloy aluminum flat plates, and the failure modes of the projectiles and the targets. The second set of one-third-scale experiments was conducted with a 14.5-mm powder launcher. The objective of the experiments was to determine the ballistic limit speed of 6Al-4V alloy titanium, high-fineness ratio projectiles centrally impacting 6Al-4V alloy titanium flat plates and the failure modes of the projectiles and the target. Radiography was employed to observe a projectile just before and after interaction with the target plate. Early in the experiment, a nondamaging, “soft-catch” technique was used to capture projectiles after they perforated the targets. Once it was realized that a projectile was not damaged during interaction with the target, a 4-inch-thick 6061-T6 alloy aluminum witness block with a 6.0- by 6.0-inch cross section was used to measure projectile residual penetration thereafter. The following data was recorded and tabulated below: projectile impact speed, projectile residual (postimpact) speed, projectile failure mode, target failure mode, and pertinent comments for the experiments. The ballistic techniques employed for the experiments were similar to those employed in an earlier study [1]. 2. EXPERIMENTAL TECHNIQUES AND SPECIMEN CONFIGURATION. 2.1 TITANIUM PROJECTILES AND ALUMINUM PLATE TARGETS. 2.1.1 Launch and Measurement Techniques. In order to launch projectiles of very low mass at repeatable speeds (under the same launch conditions) from the LLNL standard 14.5-mm single-stage powder gun, the breech mechanism was modified. Because the projectile speed range of interest was 200 fps to 1000 fps, neither conventional cartridge cases filled with powder nor ullage fillers within the cases to reduce the volume of powder would provide both sufficiently low speed and repeatability. The conventional 14.5-mm powder breech was replaced with a low-pressure (and low-cost) solenoid activated reservoir gas breech, as shown in figures 1 and 2, respectively. A 300 psi fast-acting solenoid was installed. This change resulted in reliable projectile speeds between 195 fps and 735 fps for projectiles ranging in mass from 2.0 to 9.5 grams. However, even a fast-acting 1 solenoid is relatively slow. The slow reaction time of the solenoid places an upper bound on projectile speed because the pressure buildup within the gun is limited. The air breech was not needed for higher projectile speeds. For higher projectile speeds in this projectile mass range, the ullage filler technique employing conventional small arms propellants is usually employed by LLNL. FIGURE 1. SOLENOID ACTIVATED GAS BREECH FIGURE 2. GAS BREECH, LAUNCHER, CHRONOGRAPH, AND PROJECTILE TRAP 2 Each projectile was seated in a sabot (projectile carrier) before being placed in the launcher.