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Proceedings i Si*** *"r .JJS ,#»*'' 10th U.S. Army Gun Dynamics Symposium April 23-26, 2001 Austin, Texas TH U.S. ARMY GUN 10 DYNAMICS SYMPOSIUM PROCEEDINGS Proceedings from a symposium sponsored by the Institute for Advanced Technology and Benet Laboratories, held April 23-26, 2001, in Austin, Texas. Edited by Dr. Mehmet Erengil DISTRIBUTION STATEMENT A Approved for Public Release Distribution Unlimited 20020718 233 Published by: Institute for Advanced Technology The University of Texas at Austin 3925 W. Braker Lane, Suite 400 Austin, TX 78759-5316 (512)232-4400 April 2002 IAT.CW 0065 The Institute for Advanced Technology (IAT) hosted this symposium under the sponsorship of Benet Laboratories of TACOM-ARDEC. The views and conclusions contained in this document are those of the contributor concerned, and should not be interpreted as presenting the official policies or position, either expressed or implied, of the Department of the Army or the U.S. Government unless so designated by other authorized documents. Citation of manufacturer's or trade names does not constitute an official endorsement or approval of the use thereof. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation hereon. PROCEEDINGS OF THE 10™ U.S. ARMY GUN DYNAMICS SYMPOSIUM Contents Preface vii Symposium Organization viii INVITED PRESENTATION Overview on the German R&D Programs on ETC Gun Technologies for Main Battletank Weaponization T. H. G. G. Weise 1 STRUCTURAL DYNAMICS OF CONVENTIONAL GUNS On the Design of Magneto Rheological Recoil Dampers for Fire Out of Battery Control M. Ahmadian and R. Appleton 9 Muzzle Motion Measurements for the M198 When Fired at 30 and 45 Degrees J. M. Gamer, B. J. Guidos, and B. J. Patton 25 A Fire Out of Battery Tank Gun: Theory and Simulation E. Kathe and R. Gast 37 Robust Control Design for the Elevation Axis Stabilization of the M256E1 Long Gun V. R. Marcopoli, M. S. Ng, and C. R. Wells 49 A Chatter Box: Investigation of Dynamic Response across a Gap G. P. O'Hara 67 Propagation of Longitudinal Waves in a Gun Barrel /. Randrianangaly, J. Renard, B. Campion, and E. Petitpas 80 Main Battle Tank Flexible Gun Tube Disturbance Model - Three Segment Model H.J. Sneck 92 Discussion of Fire Out of Battery Test Results M. Tedesche, R. Durocher, and M. Gully 107 GUN DYNAMICS CONTRIBUTION TO ACCURACY AND PERFORMANCE Smart Isolation Mount for Airborne Guns D. Allaei, D. J. Tarnowski, M. S. Mattice, and R. Testa 121 The Dynamic Modelling of a Novel Design of 120mm APFSDS Training Round D. N. Bulman andJ. G. Ferries 133 Adaptive Gun Barrel Vibration Absorber A. G. Littlefield and E. L. Kathe 140 PROCEEDINGS OF THE 10™ U.S. ARMY GUN DYNAMICS SYMPOSIUM A Shot Accuracy Model for Predicting the Firing Performance of a Direct Fire Weapon System D. W. Lodge and A. M. Dilkes 152 Comparison between the M256 120-mm Tank Cannon Jump Test Experiments and ARL's Gun Dynamics Simulation Codes for Prototype KE J. F. Newill, B. J. Guidos, and C. D. Livecchia 160 Launch Dynamics of the 120-mm M831A1 HEAT Training Projectile J. F. Newill, J. M. Gamer, K. P. Soencksen, and C. P. R. Hoppel 176 The Influence of Projectile Mass upon Precision E. M. Schmidt and H. L. Edge 193 Comparison of the 120-mm M831A1 Projectile's Experimental Launch Dynamic Data with Hydrocode Gun-Projectile Dynamic Simulations K. P. Soencksen, J. F. Newill, J. M. Garner, and P. Plostins 200 INTERIOR BALLISTICS: GAS DYNAMICS, WEAR AND EROSION, THERMAL EFFECTS Modeling of Barrel/Projectile Interaction in a Rotating Band P. C. T. Chen and M. Leach 213 Gun Tube Surface Kinetics and Implications P. J. Conroy, M. J. Nusca, C. Chabalowski, and W. Anderson 224 Internal Ballistics Analysis for the RAVEN Propulsion System S. Dunn, J. French, D. Coats, E. Kathe, R. Dillon, S. Sopok, and M. Witherell 236 Recoil Reduction Using Propellant Gas E. Kathe 247 Relative Erosivity of Nitramine Gun Propellants with Thermoplastic/Elastomer Binder Systems C. S. Leveritt, P. J. Conroy, and A. W. Johnson 258 Cannon Coating Erosion Modeling Achievements S. Sopok, S. Dunn, P. O'Hara, D. Coats, G. Pflegl, and C Rickard 265 ELECTROMAGNETIC LAUNCH DYNAMICS AND INTEGRATED LAUNCH PACKAGES Inductiveless Rail Launchers for Long Projectiles Y.A. Dreizin 279 On the Parasitic Mass of Launch Packages for Electromagnetic Guns M. J. Hinton, N. R. Cooper, D. Haugh and M. A. Firth 291 PROCEEDINGS OF THE 10™ U.S. ARMY GUN DYNAMICS SYMPOSIUM Use of the SIMBAD Gun Dynamics Code for Modelling the In-Bore Dynamics of EM Launchers D. W. Lodge and A. M. Dilkes 305 Results of a Study for a Long Range Coilgun Naval Bombardment System S. Shope, J. Alexander, W. Gutierrez, R. Kaye, M. Kniskern, F. Long, D. Smith, B. Turman, B. Marder, A. Hodapp Jr., and R. V/averik 320 Critical Velocity of Electromagnetic Gun In Response to Projectile Movement J. T. Tzeng 332 HIGH PERFORMANCE MATERIALS FOR CONVENTIONAL AND ELECTROMAGNETIC LAUNCHERS Reinforced Metal Structural Jackets for Advanced Gun Barrels J. M. Burnett, H. Gigerenzer, E. Pennell, and C. Dampier 341 Investigation of Tungsten, Copper, and Silver Alloys with Indium at the Rail-Armature Interface on a Railgun Test Bench D. Gillich and W. Maier 355 Concepts for Fieldable Electromagnetic Gun Barrels M. J. Hinton, A. Howard, N. R. Cooper, D. K. Wallington and M. A. Firth 369 Large Caliber Gun Tube Materials Systems Design J. S. Montgomery and R. L. Ellis 385 IN-BORE DIAGNOSTICS, TESTING AND INSTRUMENTATION Off the Shelf Technology for Gun Barrel Straightness Measurement J. Garner, T. Marrs, T. Erline, and M. Bundy 398 Performance Enhancement and Health Monitoring of a Medium Caliber Gun System Using Optical Fiber Bragg Grating Sensors C. LaVigna, J. Bowlus, H. Kwatny, S. Chen, H. Zhang, and S. Cytron 406 Investigating UHF Telemetry for Electromagnetic Launchers S. Levinson, L. Burke, M. Erengil, and J. Faust 418 Use of an Instrumented 120mm Projectile for Obtaining In-bore Gun Dynamics Data D. W. Lodge and A. M. Dilkes 433 Visual Characterization of Wear in Large Caliber Weapons D. Salafia 444 Stereo at the Speed of Light: High-Speed Digital Stereo Imaging at up to 100 Million Frames per Second D. R. Snyder, E. R. Chenette, R. D. Hudson, R. P. Young Jr., D. W. Gardner, and P. E. Nebolsine 454 PROCEEDINGS OF THE 10™ U.S. ARMY GUN DYNAMICS SYMPOSIUM Complete Bore Centerline Extractor and Surface Mapper R. Von Wahlde, T. Erline, M. Kregel, and M. Bundy 465 NOVEL LAUNCH TECHNIQUES Optimizing a Slingatron-Based Space Launcher Using MATLAB® M. Bundy, G. Cooper, andS. Wilkerson 474 Numerical Simulations of the Slingatron G. R. Cooper, D. A. Tidman, M. Bundy, andS. Wilkerson 491 Slingatron: A High Velocity Rapid Fire Sling D. A. Tidman • 509 Author Index. .527 Preface This volume contains the papers presented at the 10th U.S. Army Gun Dynamics Symposium held in Austin, Texas on April 23-26, 2001. The contents of this volume, as well as the invited talks, are also published in an accompanying CD-ROM. Initiated in 1976, the biennial Gun Dynamics Symposium has been providing a forum for discussion of applied research and engineering solutions in collective disciplines of structural dynamics, interior ballistics, exterior ballistics, advanced materials, and multidisciplinary design optimization for high- performance cannon weaponry. In this 10th Symposium, the technical committee has expanded the scope of the meeting and integrated electromagnetic gun discussions with conventional weapons systems and, for the first time, implemented a peer review process. Each technical paper in this volume has undergone peer review by experts in their respective fields of research. A special note of thanks goes to the members of the technical committee for supporting and enabling these changes. The authors are commended for keeping to the schedule imposed by the review process. The 10th Gun Dynamics Symposium was attended by 114 scientists and engineers representing the United States and the European countries. The Institute for Advanced Technology (IAT) hosted this symposium under the sponsorship of the Benet Laboratories of TACOM-ARDEC. Mr. Eric Kathe (TACOM-ARDEC Benet Laboratories) was the Symposium Chairman; and Dr. Mehmet E. Erengil (IAT) and Dr. Peter Plostins (Army Research Laboratory, ARL) were the Technical Chairmen. The technical agenda included 39 oral presentations and 13 poster presentations. A series of invited speakers discussed a broad spectrum of relevant topics including research and development efforts and engineering applications in both U.S. and European programs. The keynote addresses were given by Dr. Hans Mark (DDR&E) and LTG Paul Kern (Military Deputy, ASAALT). Invited talks featured presentations by distinguished speakers Dr. Marilyn Freeman (DARPA), Mr. Richard Hassenbein (TACOM-ARDEC Benet Laboratories), Mr. Michael Hermanson (UDLP), Professor Mike Hinten and Mr. David Wallington (DERA, UK), LTC Albert Tanner (ARL), and Dr. Thomas H.G.G. Weise (Rheinmetall W&M GmbH, Germany). In addition, Mr. Robert Sackheim (NASA-MSFC) moderated a special panel discussion on "Gun Launch to Orbit." The expert panel included Mr. John Cole (NASA-MSFC), Dr. Miles Palmer (SAIC), Dr. Ian McNab (IAT), and Dr. Edward Schmidt (ARL). The panel discussion was one of the highlights of the meeting. The programmatic changes implemented in this symposium — namely the inclusion of electromagnetic gun technology within the conventional weapons systems community and the peer review process — have both proven to be extremely successful. The electromagnetic gun technology promises an undeniably revolutionary improvement in weapons systems capabilities. Cross-fertilization of ideas within the entire gun community could only help accelerate the implementation of this technology. I not only look forward to future symposia organizers to embrace the programmatic changes implemented here but also challenge the leadership to seize upon this opportunity and help accelerate the development of electromagnetic gun weapons systems. Last, but not least, I am fully indebted to Ms. Michelle Ramsey and Ms. Janet Monaco who worked diligently to coordinate all aspects of the symposium and assemble these proceedings. The success of the symposium is largely due to their dedicated commitment and attention to detail. Thank you both! Mehmet E. Erengil Technical Co-Chairman Institute for Advanced Technology 10™ U.S. ARMY GUN DYNAMICS SYMPOSIUM Austin, Texas April 23-26, 2001 Symposium Chairman Eric Kathe Technical Chairmen Mehmet Erengil Peter Plostins Committee Members Edward Alexander Joel Leifer David Bauer William Oberle Larry Burton Mohan Palathingal Robert Dillon Chadee Persad Roger Ellis Edward Schmidt Ron Gast John Vasilakis Frank Hoogterp James Wildman Organizing Committee Mehmet Erengil Janet Monaco Eric Kathe Michelle Ramsey Overview on the German R&D Programs on ETC Gun Technologies for Main Battletank Weaponization Thomas H.G.G. Weise Rheinmetall W&M GmbH Heinrich-Erhardt-Strasse 2, D-29345 Unterlüß Federal Republic of Germany Abstract In order to improve the performance of large calibre guns for main battlefield tank applications a wide range of R&D programs have been performed in Germany on electric and electrically supported barrel guns since 1980. In the beginning pure electric gun technologies were investigated including rail, coil and electrothermal acceleration methods. A large calibre 105mm electrothermal gun demonstrator supplied by a 30 MJ capacitive pulsed power supply system was introduced in 1995. Muzzle velocities up to 2.4 km/s were optained with this set-up resulting in muzzle energies up to 5.8 MJ. The missing perspective on solving the energy density requirements of the pulsed power supply technology for a system realization led to the termination of these programs in the beginning of 1996. Due to its limited electrical energy requirements the technology of ETC guns has been investigated during the last years with high priority. It is the goal to provide a future main battle tank gun with increased firepower for integration into the next generation of combat fighting vehicles. Current R&D programmes result in a demonstration of the interior ballistic performance of the different ETC concepts. 120mm ETC demonstrators are used to perform this demonstration. The presentation gives a short briefing on the results of the former investigations on pure electric guns and introduces the background for deciding to terminate these efforts. In the following an overrview on the R&D Structure of the German programs on ETC and its related technology fields is presented. Basic investigations led to the definition of different ETC concepts for the realization of electrothermal plasma ignition methods and electrothermal combustion control of ETC tailored propellants and charge designs. Based on the results of 105mm firings and of interior ballistic simulations a 120mm ETC cartridge was designed and investigated experimentally. First 120mm firing results will be given. The presentation concludes in giving an outlook on the perspectives of the performance of ETC technologies and its power supply technologies in order to provide the access to increased firepower and survivability of existing and succeeding main battle tank systems without leaving the currently introduced boundary conditions of the large calibre weapons. 1 Introduction Improved protection technologies by active and reactive armor as well as by increased hardeness of armor plating technologies define the requirements of the performance of future tank guns. Improved missile technologies as well as multiple low cost cruise missile attacks will be the challenges for future anti air defence guns. Military operations in urban terrains define new requirements for medium calibre guns for future vehicles. For the existing conventional guns a high level of lethality has to be provided which can be obtained i.e. from improved temperature insensitive propellants. Future guns have to provide a significantly higher lethality which can be oc-tained from advanced propulsion and gun technologies. These requirements have been adressed by the R&D programmes on electric and