Experimental facility
Experimental facility
Single-stage Powder Gun with Pressure Shear Capability and a velocity range of 0.2 to 1.8 km/s: The single-stage powder gun has a slotted barrel with a bore diameter of 40 mm capable of accelerating 200 g projectiles to 2.0 km/s. The gun Utilizes the photonic Doppler velocimeter for normal and transverse velocity measurements.
Two-stage light gas gun with a velocity range of 1.0 to 7.0 km/s: The two-stage powder gun has a barrel with a bore diameter of 12.7 mm. It can accelerate projectiles to 5.0 km/s, allowing us to probe high-pressure equations of state and shock structure in materials. This gun is also utilizing high speed PDV velocity measurements.
Laser flyer plate and particle impact facility: The laser flyer plate impact experimental setup is developed using a 3.5 J, 7 ns laser. The maximum velocity of the aluminum flyer with 50 µm with 500 µm diameter is 3.0 km/s. These experiments can obtain short pulses, which cannot be achieved using gas or powder guns.
Conventional tension and compression Hopkinson bars (strain rates vary from 103 to 104 /s): The lab has dynamic compression and tension split Hopkinson pressure bars. By changing the bar materials, experiments can be performed on soft materials or ceramics. The dynamic compression Hopkinson bar also has a 3-bar configuration to perform the 3-point dynamic fracture measurements.
Small-scale Hopkinson bar to reach shockless high-rate experiments (strain rates vary from 104 to 105 /s): The lab has built a small-scale Hopkinson bar with a bar diameter of 1000 µm, allowing us to attain strain rates close to 105 /s. These experiments have laser-based particle velocity measurements and in-situ microscale deformation measurements.
Automated split Hopkinson bar strain rates vary from 103 to 104 /s: We developed a fully automated split Hopkinson bar to conduct a large number of experiments for data-driven material models. The experimental setup can reload the sample, reposition the bars, rearm the gas gun with the projectile, and automate data acquisition and analysis. It can perform 60 experiments at strain rates varying from 103 to 104 /s in an hour.
Instrumentation and data acquisition: Instrumentation includes a 6-channel Photonic Doppler velocimeter with 12 GHz and 34 GHz photodetectors. This PDV has 5 Normal velocity measurement channels and 1 Shear velocity measurement channel. The data acquisition is performed with the help of two Oscilloscopes. The highest-speed oscilloscope has a bandwidth of 12 GHz and 100 GS/s data acquisition speed, and the slower one has a bandwidth of 7 GHz and 20 GS/s acquisition speeds. Photodetectors for the PDV have a 12 to 25 GHz speed, with rise time in sub nanoseconds. The lab has three more oscilloscopes (Bandwidths 1 GHz, 400 MHz, and 200 MHz, with an acquisition speed of 10 GS/s, 1 GS/s, and 1GS/s, respectively) for different data acquisition purposes. Density and sound velocity measurement stations are also available in the lab.
High speed imaging and digital image correlation: The lab has one Shimadzu HPVX-2 camera with an image acquisition speed of 10 million frames/s. The lab also has state-of-the-art 2D and 3D digital image correlation postprocessing software from Correlated Solutions.
Sample preparation equipment: A 10-inch diameter lapping machine from Lapmaster-Wolters, an automatic polisher from Buehler, a vibratory polisher from Buehler, and a diamond saw from Allied are available for preparing the samples for experiments and microstructural characterization.