LLNL Mechanics Of Materials Gas Gun
Format
SOECS Senior Project Demonstration
Abstract/Artist Statement
The Mechanics of Materials Group at Lawrence Livermore National Laboratory desired a gas gun capable of firing a 2.5 lbm flier at 100 m/sec. The gun design had to incorporate commercially available equipment and minimize maintenance requirements. The gun will be used for Split Hopkinson Bar testing, Dynamic Fracture experiments, and must be versatile enough for future unforeseen projects. The final gas gun design uses a commercial 24 gallon air tank as a pressure source. The gun is fired by energizing a 2” solenoid operated valve. The valve is connected to the breech of the gun with a flexible hose, which eliminates hard plumbing alignment issues. The breech can be opened to allow access for system alignment and changing projectiles. The barrel is comprised of three sections of honed tubing with threaded ends. The sections can be connected in multiple orientations to allow different velocity ranges. The gun is operated by pressurizing the air tank to a fire pressure based on desired projectile velocity, and then energizing the solenoid through the fire control circuit. The solenoid opens allowing the pressure to act on the back of the flier. The pressure acting on the flier accelerates it down the barrel. Flier velocity at the end of the barrel is a function of the barrel length and the initial fire pressure. In the 21 foot barrel configuration and air pressure at 125 psi, a 2.5 lbm flier will reach 100 m/sec.The gun components are being manufactured both at the Laboratory and University of the Pacific. The gun is being assembled in place at the Laboratory. The gun will expand the current capabilities of the test group and improve test set up and turnaround time.
Location
Pacific Geosciences Center
Start Date
30-4-2005 2:00 PM
End Date
30-4-2005 5:00 PM
LLNL Mechanics Of Materials Gas Gun
Pacific Geosciences Center
The Mechanics of Materials Group at Lawrence Livermore National Laboratory desired a gas gun capable of firing a 2.5 lbm flier at 100 m/sec. The gun design had to incorporate commercially available equipment and minimize maintenance requirements. The gun will be used for Split Hopkinson Bar testing, Dynamic Fracture experiments, and must be versatile enough for future unforeseen projects. The final gas gun design uses a commercial 24 gallon air tank as a pressure source. The gun is fired by energizing a 2” solenoid operated valve. The valve is connected to the breech of the gun with a flexible hose, which eliminates hard plumbing alignment issues. The breech can be opened to allow access for system alignment and changing projectiles. The barrel is comprised of three sections of honed tubing with threaded ends. The sections can be connected in multiple orientations to allow different velocity ranges. The gun is operated by pressurizing the air tank to a fire pressure based on desired projectile velocity, and then energizing the solenoid through the fire control circuit. The solenoid opens allowing the pressure to act on the back of the flier. The pressure acting on the flier accelerates it down the barrel. Flier velocity at the end of the barrel is a function of the barrel length and the initial fire pressure. In the 21 foot barrel configuration and air pressure at 125 psi, a 2.5 lbm flier will reach 100 m/sec.The gun components are being manufactured both at the Laboratory and University of the Pacific. The gun is being assembled in place at the Laboratory. The gun will expand the current capabilities of the test group and improve test set up and turnaround time.