REL Designs, Builds, and Ships Mini-SHPB – July 19, 2017
Built on the same expandable, modular platform all GEN-3 SURE-Test SHPB systems sit, REL designed and manufactured a miniature compression Split Hopkinson Pressure Bar system. This mini-system is currently setup with 1/8” (3mm) diameter x 32” (812mm) long bars with a momentum trap, but it can be scaled up or down very easily. The architecture is open to allow for the integration of all REL’s standard add on SURE-Test modules. (REL’s Camera and high intensity lighting is demonstrated in the image below).
A scaling down of SURE-Launch was needed to propel 1/8” diameter striker bars at reasonable speeds. This manually fired launcher will propel the system’s striker bars 120 fps at 50 psi. While this does not sound dramatic, controllable and consistent strain rates of over 12000/s have been achieved on aluminum specimens.This system integrates a 2-channel SURE-DAQ, a full acquisition system, and all data is processed through REL’s SURE-Pulse free open-source software.
One-eighth inch diameter bars offer some challenges in SHPB testing. One of the challenges is mounting the strain gages. A microscope is used to mount and check the dynamic 3mm gauges to the bars as seen below.
Bar alignment is achieved through REL’s unique bird-mouthed bar supports locked onto the keyed SURE-Flat base. The alignment of the 1/8” diameter bars is insured when the bushings bottom out into precision-machined bar supports. This feature allows for efficient interchanging of bars (i.e. steel to aluminum) for different tests.
This single rail platform also integrates a workstation shelf where the data acquisition system and computer reside. This shelf was widened in this system to allow the system operator to layout specimens to be tested, striker bars and run all data processing after testing.
High strain rates are more easily achieved in smaller diameter samples. These samples are conveniently test with this system. Researchers testing multi-layered materials, where quantification of the each of the layers is needed, will see great advantages to using this robust mini system.Call REL for more information on our latest innovation. (906-337-3018).