Manfred Held
In World War II non-deforming kinetic energy (KE) projectiles with velocities beneath 1 000 m/s achieved perforation of the target by volume deformation and/or plugging. The design of KE projectiles has changed significantly as muzzle velocities have increased, leading to much higher impact velocities. For projectile velocities above 1 000 m/s the mechanisms of volume deformation and plugging are replaced by hydrodynamic penetration, where the projectiles are eroding during the penetration process. This paper provides a brief tutorial on the penetration of KE rounds for projectile velocities below and above 1 000 m/s. The corresponding penetration equations are described, after which the paper presents a useful rule-of-thumb, the experimentally obtained diagram of Hohler and Stilp, and an analytical equation by Lanz, Jeanquartier and Odermatt. The paper concludes with a numerical example.
J. Wang and R. Bartholomeusz
Ballistic tests were carried out using carbon/epoxy composite panels and standard ball munitions. Impact and residual velocities of the projectiles and damage area, including delamination, of the test panels were measured. FATEPEN prediction and Dyna3D simulation were conducted. Residual velocities and hole areas predicted by FATEPEN are comparable to, but do not accurately agree with, the measured residual velocities and the visible damage areas on the specimens. Residual velocities predicted by Dyna3D are closer to the measured velocities. Similar to the FATEPEN prediction, hole areas predicted by Dyna3D are comparable to the visible damage areas on the specimens. Delamination areas predicted by Dyna3D appear to agree with the measurement reasonably well. Hence Dyna3D appears to be a useful tool for evaluation of delamination and thus structure residual strength of composite panels after ballistic impact.
David J. Purdy and Dave Simner
Many military vehicles are being developed which use a hybrid electric drive system. Of these, a number utilise drive motors mounted within some or all of the road wheels. Of necessity these wheel-motor assemblies are somewhat heavier than the similar, existing, conventional road wheels. This extra mass has implications for both the ride within the vehicle and the design of the suspension-wheel-motor system. This paper looks at the implications of the extra mass within the wheel assembly as it increases the unsprung mass of the vehicle. Linear and non-linear single-wheel station models have been developed in order to quantify the effects of the modified design. A range of sprung-to-unsprung mass ratios have been analysed using the models. The behaviour of the vehicle at a range of speeds and different obstacles has been simulated. The results show the predicted accelerations and vibration dose value (VDV) vary with both speed and sprung-to-unsprung mass ratio. The behaviour of the suspensions for the random ride and step impact conditions show that the ride quality and acceleration levels deteriorate with vehicle speed. For the pothole simulation, however, the higher unsprung mass conditions show an improvement in some aspects as speeds increase, because the wheel effectively ‘skips over’ the pothole and the resultant impact is reduced.
Patrick J.H. Wormell and David J. Purdy
Determining the handling characteristics of tracked vehicles is significantly more complex than wheeled vehicles. This is because of the non-linear behaviour of the interaction between the tracks and ground during turning. In many cases a full dynamics model of the steering of a tracked vehicle is too complex and time consuming to generate and gives little or no insight into the mechanics of skid steer. This is especially true during the initial design phase, or the examination of a modification, when the designer needs a method, which allows the trade offs to be examined quickly. The work presented here is based on the method used at the Royal Military College of Science (RMCS) to teach the fundamentals of tracked vehicle steering and is suitable for low speed predictions only. Comparison of the method with experimental data shows that the radius of turn is determined with reasonable accuracy but only an upper bound is put on the sprocket torque. Modifications of this technique to include side force generation have been used successfully elsewhere to determine the behaviour of half-tracks and articulated track vehicles.
Geoffrey N. Hone, Robert Ayres and Lynne Martin
This paper considers a number of themes, and seeks to show that they should be considered jointly rather than severally. First the historical aspect of technology is considered as applied to data transmission, particularly for command and control (C2) data. Next, the paper discusses a standard language for modelling command and control in combat situations, and how this could be extended from use in synthetic environments to the modern network-enabled forces. It is argued that a command or battlespace modelling language intended to ensure compatibility between simulation platforms can be developed for practical use in the modern digitized force. The object of this would be to minimise the “display fixation” which has already been shown to occur with battle management displays. The paper then considers C2 messaging in the fields of civil aviation and ground combat and considers lessons learned on the effect of changes in aircrew workload and behaviours brought about by the use of data link displays for message transmission. The paper concludes that modern battlefield command systems can potentially be improved by the use of techniques borrowed from other domains.
David R. Wilton
Most modern military forces have embraced simulation as an effective and cost-efficient means of preparing and training for military operations. While there is now a well-developed military simulation industry, and strong anecdotal evidence of the benefits of simulations abounds, solid evidence of benefits, and monetary savings accruing, is problematic. This paper provides a basis for demonstrating the benefits of simulation in a military environment. The paper describes current initiatives to define the benefits of simulation in military forces, suggests a possible methodology or framework for measuring benefits, and provides brief details of evidence of benefits, as realized by US military forces.
Jared S. Knutzon, Bryan E. Walter, Adrian V. Sannier and James H. Oliver
More than ever before, success in battle depends on effective command and control—but the increasing complexity and speed of modern engagements makes it ever more difficult to develop the comprehensive situational awareness upon which effective command and control depends. In the face of this increase in pace and complexity, developing systems to expose cost-effectively battle managers and weapons directors to the full range and scope of potential conflict situations is an ever-increasing challenge. This paper presents a distributed immersive command and control visualization system. Networked participants visualize and interact with the Virtual Battlespace based on a JSAF simulation from the first-person, tactical or strategic viewpoints using one of several different immersive devices. This paper also describes how the Virtual Battlespace visualization system can be extended for use in a variety of control tasks such as battle manager training, real-time command and control, and UAV swarm management. Battle managers can interact with both simulated and “manned” entities using a mixed mode interface that includes wireless palmtop interaction. The system has been developed under the guidance of the Iowa National Guard’s 133rd Air Control Squadron, which has also cooperated in the evaluation of the system.
J.W. McCauley, et al (eds), Ceramic Armor Materials By Design (Ceramic Transactions, Volume 134), The American Ceramic Society, Westerville, Ohio, 2002 (ISBN 1-57498-148-X).
