In situ damage assessment using synchrotron X-rays in materials loaded by a Hopkinson bar.
Split Hopkinson or Kolsky bars are common high-rate characterization tools for dynamic mechanical behaviour of materials. Stress-strain responses averaged over specimen volume are obtained as a function of strain rate. Specimen deformation histories can be monitored by high-speed imaging on the surface. It has not been possible to track the damage initiation and evolution during the dynamic deformation inside specimens except for a few transparent materials. In this study, we integrated Hopkinson compression/tension bars with high-speed X-ray imaging capabilities. The damage history in a dynamically deforming specimen was monitored in situ using synchrotron radiation via X-ray phase contrast imaging. The effectiveness of the novel union between these two powerful techniques, which opens a new angle for data acquisition in dynamic experiments, is demonstrated by a series of dynamic experiments on a variety of material systems, including particle interaction in granular materials, glass impact cracking, single crystal silicon tensile failure and ligament-bone junction damage.
School of Material Science, Purdue University, , West Lafayette, IN, USA.
Weinong W
WW
Chen
Matthew C
MC
Hudspeth
Ben
B
Claus
Niranjan D
ND
Parab
John T
JT
Black
Kamel
K
Fezzaa
S N
SN
Luo
Hopkinson bar; X-ray; dynamic response; granular materials; phase contract imaging; synchrotron radiation