Library
March 1998
This paper reviews the traditional selection criteria for shaped charge liners, and demonstrates some confusions that arise. When considering possible new liner materials it is proposed that measurement of dynamic mechanical properties, rather than the usual more readily available static data, would be helpful, particularly to mathematical modellers.
A study was conducted to compare the high velocity penetration performance of segmented-rod projectiles of various spacer and segment lengths with that of continuous rod projectiles of the same mass and diameter. A high-pressure pre-burned propellant gun was built for this study. Analytical models by Tate and Charters were used to predict the penetration performance predicted. Computer simulations using the AUTODYN 2D package were run to study the penetration process. It was predicted that at velocities around 1800 ms-1 and above, the performance of the steel-segmented rods was much superior to continuous rods. In trials, a 5-segment rod, with spacing of l/d=2.25, fired at 1800 ms-1, achieved a penetration performance 44% higher than continuous rods of similar mass and diameter fired at similar velocities. Simulation of segmented projectiles with 10 segments, compared to continuous rod of similar mass and diameter, impacting at 3000 ms-1, produces an increase of 59% penetration.
Two grades of armour ceramic have been subjected to high velocity impact by small steel spheres. The depth of penetration, crack formation and the extent of comminution have been characterised. In particular the formation of the Hertzian-type conical fractures has been analysed and compared with other experimental results. A ranking method has been employed to calculate the relative mass advantage of using a ceramic over an aluminium material. It is found that, for this experimental programme, using a harder alumina of lower fracture toughness provides better protection than that given by a softer, tougher grade. However, the advantage of using this ceramic diminishes as the impact velocity is increased. This paper will be interest to the armourer who is concerned with high explosive fragmenting ammunition.
Armoured vehicles are heavy masses of metal embodying many heat-generating systems, and are generally inhospitable enclosures for the crew they carry. The many tons of metal in their construction take up a mean temperature of the environment in which they are operating, and possess, as a result of that mass, a long time constant, which slows down the rate at which the temperature of the structure can change. The vehicle crew requires an environment controlled within fairly close limits to preserve their operating efficiency, and even their lives. This paper examines the factors influencing the effects on the vehicle in a hot climate; the relatively small environment envelope needed by the crew; and the steps that can be taken to achieve that envelope in such hostile conditions. Some engineering problems and their solutions are also examined, together with their effects on overall vehicle design.
New computer and communications technologies have the potential to revolutionize the battlefield. However, developing battlefield command systems that take advantage of these new technologies before they become obsolescent is a challenge for procurement professionals. Traditional acquisition strategies are inherently inflexible, and are therefore not well suited to these systems with their high rate of technology advancement and often volatile user requirements. Evolutionary Acquisition (EA) is a new strategy, recently introduced in the Australian Defence Organization, with the potential to deliver these systems more efficiently. This paper provides an overview of the principles behind EA, the characteristics of systems suited to the EA approach and the benefits that can be achieved. The challenges in successfully completing an EA project are also discussed.
The overlap in requirements of military and commercial information systems is steadily growing. Wider use of Commercial-Off-The-Shelf (COTS) information technology in military systems offers the prospect of reduced development and support costs, improved functionality and improved interoperability. However, COTS products also introduce risks related to reliability, security, supportability and dependence on commercial product cycles.
One of the most challenging issues facing the Australian Department of Defence is provision of high data rate links to tactical platforms to support future generation command and control, surveillance, intelligence, logistics and administrative networks. Recently, a window of opportunity arose to place a military payload onboard a civilian spacecraft bus. This paper provides an overview of the proposed military payload and some of its potential applications.
Surveillance and target acquisition (STA) form one of the five key sub-systems that combine to make up a guided weapon (GW). This paper addresses the role of STA in GW systems. It identifies the key principles that can be used to select an STA sub-system to suit a particular application. A classification of types of STA is then proposed and finally, some of the GW-STA interface problems are discussed, including the issue of keeping the human somewhere in the STA-GW decision loop.
This review article outlines the operational requirement for Battlefield Surveillance Radar, and the design challenges that result. It is shown that the clutter problem on the battlefield leads to a Pulse Doppler solution. Design requirements are outlined and a typical current design is addressed. Possible future developments are discussed, and it is argued that future developments will be driven by the need for covert operation, with a drive towards active phased array antennas and LPI waveforms. In both cases, this takes advantage of expected advances in technology, and will lead to a more effective equipment.