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Mechanical Behaviour of Baseball and Softball Bats
Published in Franz Konstantin Fuss, Aleksandar Subic, Martin Strangwood, Rabindra Mehta, Routledge Handbook of Sports Technology and Engineering, 2013
Currently, all certified bat performance tests involve an initially stationary bat and a pitched ball (this is the only aspect that is common among the various associations regulating bat performance). The balls are accelerated using an air cannon, and travel inside a ‘sabot’. The sabot is sized to the cannon barrel which improves speed control, positional accuracy and prevents ball rotation. The sabot remains inside the cannon. After the ball exits the cannon, it passes through light gates which measure its incoming speed. After impact the speed of either the rebounding ball (‘ball out’) and/or the recoiling bat (‘bat out’) is measured. Angular momentum about the pivot is conserved during the bat–ball impact. It is experimentally easier and more accurate to measure two speeds and use angular momentum to find the third speed. The angular momentum balance of a bat-ball impact of a pivoted bat is −mvPq+Ivsq=mvkq+Iv′sq
Ammunition Design Practice
Published in Donald E. Carlucci, Sidney S. Jacobson, Ballistics, 2018
Donald E. Carlucci, Sidney S. Jacobson
Sabots (French for “wooden shoe”) are used in both rifled and smoothbore guns to allow a standard weapon to fire a high-density, streamlined subprojectile whose diameter is much smaller than the bore, at a velocity higher than would normally be possible if the gun were sized to the diameter of the subprojectile. Discarding sabots have been in general use since the Second World War and are still popular (in fact, an artist’s rendition of a discarding sabot is illustrated on the cover of this book). They are called “discarding sabots” since they are shed from the subprojectile at the muzzle allowing it to fly unencumbered to the target.
Bullets, Blast, Jets and Fragments
Published in Paul J. Hazell, Armour, 2023
It is clear that reducing the diameter of the penetrator is important for increasing the level of penetration. Indeed, this is partly the reason why sub-calibre projectiles were invented in World War II. It was soon discovered that reducing the diameter of the round and housing it within a lightweight sabot, whilst maintaining a relatively large calibre of gun, improved penetrability dramatically.
Fragmentation characteristics of PELE shell perforating thin metal target plate
Published in Mechanics of Advanced Materials and Structures, 2022
Chun Cheng, Lizhi Xu, Zhaojun Pang, Zhonghua Du, Meng Wang, Xi Chen
The experimental setup and projectiles are shown in Figure 1. In the experiment, a ballistic gun with 25 mm caliber was used as launching device. The metal target plate was fixed on the target frame 6 m away from the muzzle. The sizes of the target plates are 200 mm × 200 mm × 5 mm and 200 mm ×200 mm × 10 mm. Two velocity paper target plates with on and off aluminum foil were arranged at 0.5 m in front of the target plate to measure the impact velocity of the projectile during each experiment. A water tank of 0.6 m × 0.6m × 0.6m was placed at 0.4 m behind the target plate to collect the fragments produced by the impact of the projectile shell. In order to avoid deformation and fracture of the fragments, a polystyrene foam (0.6 m × 0.6m × 0.6m) was used on the side facing the muzzle during each experiment. Plastic film was laid in the tank in order to prevent the water tank from leaking. The shell is 38.1 mm in length, 12.7 mm in diameter, and the filling is 34.1 mm in length and 9 mm in diameter. Pictures of the projectiles in Figure 1 show that the assembled projectile is composed of two parts, such as the sabot and the projectile. The sabot consists of two aluminum alloy clasps and one nylon thread ring which has a tail skirt with a diameter slightly larger than the caliber of the gun. In the process of launching, the nylon thread ring plays the role of not only assembling and fixing the aluminum alloy clasps, but also sealing the propellant gas. After flying out of the muzzle, the aluminum alloy clasps are separated because of air resistance and the loss of the restraint of the gun barrel.
Dynamic behaviors and protection mechanisms of sulcata tortoise carapace
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2021
P. Jearanaisilawong, N. Jongpairojcosit, C. Glunrawd
The impact behavior of tortoise carapace was investigated using a single-stage gas gun. The 6.35 mm steel ball bearing was used as a projectile. Since the gun barrel had a diameter of 25 mm, a plastic sabot was used to support the projectile while accelerating along the gun barrel. The sabot stripper was installed at the end of the gun barrel to stop and release the sabot from the projectile and to allow only the projectile to hit the target. The projectile with sabot was launched by compressed gas along the gun barrel and its velocity was controlled by firing pressure. A ballistic chronograph installed in front of the target was used to measure the projectile velocity. The effect of gas expansion was eliminated by the baffle installed at the end of the gun barrel. A rectangular sample was placed on the target support and held by nylon strap at the top and bottom edges. The impact responses of the carapace were examined through high speed camera (REDLAKE HS-3) images. Figure 4 illustrates the impact test setup.
Interlaminar shear property and high-velocity impact resistance of CFRP laminates after cyclic hygrothermal aging
Published in International Journal of Crashworthiness, 2020
Lulu Liu, Zhenhua Zhao, Wei Chen, Mingfu Xue, Chao Shuang
Ballistic tests were conducted using a single-stage gas gun with caliber of 37 mm, which could accelerate the projectile to a maximum velocity of 300 m/s. The picture and schematic diagram of this gas gun are shown in Figure 3(a). The blade-like projectile was placed in an aluminum sabot, supporting by several foam rings (Figure 3(b)). The projectile along with aluminum sabot were accelerated in the gun barrel under the pushing force provided by the compressive air. Therefore the launch velocity of the projectile could be changed through adjusting the air pressure. The sabot was separated at the exit of the gun barrel, while the projectile moved forward and finally impacted the target. The spallation fragments from the target and the projectile with certain residual velocity were both arrested by the collector mounted in the target chamber. A velocimeter system was installed between the gun muzzle and the target. When the projectile passed through the velocimeter system, two laser beams at a certain distance were successively obstructed, generating the step change of voltage signals. The projectile velocity could be determined by the time interval of two trigger signals and the distance.