Projectile

About: Projectile is a research topic. Over the lifetime, 13047 publications have been published within this topic receiving 115563 citations.

Impact system for ultrafast synchrotron experiments

Abstract: The impact system for ultrafast synchrotron experiments, or IMPULSE, is a 12.6-mm bore light-gas gun (<1 km/s projectile velocity) designed specifically for performing dynamic compression experiments using the advanced imaging and X-ray diffraction methods available at synchrotron sources. The gun system, capable of reaching projectile velocities up to 1 km/s, was designed to be portable for quick insertion/removal in the experimental hutch at Sector 32 ID-B of the Advanced Photon Source (Argonne, IL) while allowing the target chamber to rotate for sample alignment with the beam. A key challenge in using the gun system to acquire dynamic data on the nanosecond time scale was synchronization (or bracketing) of the impact event with the incident X-ray pulses (80 ps width). A description of the basic gun system used in previous work is provided along with details of an improved launch initiation system designed to significantly reduce the total system time from launch initiation to impact. Experiments were performed to directly measure the gun system time and to determine the gun performance curve for projectile velocities ranging from 0.3 to 0.9 km/s. All results show an average system time of 21.6 ± 4.5 ms, making it possible to better synchronize the gun system and detectors to the X-ray beam.

Electronic sensing screen for measuring projectile parameters

Abstract: A unique electronic sensing screen (44, 105) apparatus for automatically measuring various parameters of moving projectiles. Projectiles pass between an artificial (16, 18) or natural light source and light sensors (12, 14, 118, 176), resulting in signals from the sensors, which are processed into data showing projectile profiles or photo-like images, shock waves, velocity, angle of attack, and dispersion. The apparatus provides quick turn-around times between parameter measurements, such as those of many projectiles fired in rapid succession, and readily usable results.

Ballistic impact response for two-step braided three-dimensional textile composites

Abstract: We are concerned with the ballistic impact response of three-dimensional two-step braided textile composites struck by a 36.1-g hemispherical tip-ended rigid cylindrical projectile. A series of quasistatic punch tests using a hemispherical indentor have been conducted to investigate the progressive damage modes of the target and to obtain the punch load-displacement relationship. In addition, a pneumatic launcher is used to propel the projectile with incident velocities ranging from 70 to 170 m/s. The ballistic limit is experimentally determined to be near 74.1 m/s. Commercially available finite element code (MARC) is incorporated with the constitutive relationship for three-dimensional two-step braided composites and the proposed static penetration model to simulate the dynamic impact response. An energy consideration is applied to predict the projectile's residual (or terminal) velocity. Numerical simulated result based on the static elastic properties of the target tends to overestimate the projectile terminal velocity. When the target's elastic moduli used in simulation are increased by 1.5 times the static values, good agreement is found between the simulated terminal velocities and test results for projectile incident velocities ranging from 70 to 180 m/s.