Abstract
The dynamic fracture and fragmentation of a material is a complex late stage phenomenon occurring in many shock loading scenarios. Improving our predictive capability depends upon exercising our current failure models against new loading schemes and data. We present axially-symmetric high strain rate (104 s−1) expansion of Ti-6Al-4V cylinders using a single stage light gas gun technique. A steel ogive insert was located inside the target cylinder, into which a polycarbonate rod was launched. Deformation of this rod around the insert drives the cylinder into rapid expansion. This technique we have developed facilitates repeatable loading, independent of the temperature of the sample cylinder, with straightforward adjustment of the radial strain rate. Expansion velocity was measured with multiple channels of photon Doppler velocimetry. High speed imaging was used to track the overall expansion process and record strain to failure and crack growth. Results from a cylinder at a temperature of 150 K are compared with work at room temperature, examining the deformation, failure mechanisms and differences in fragmentation.
Highlights
The ability to predict the onset of fracture and the resulting fragmentation behaviour of a body is of huge importance to many fields in industry and engineering
In some applications fracture is undesirable, such as in the aerospace and structural engineering industries where being able to avoid material failure is important. Other areas such as the military need models that capture the fracture and fragmentation accurately to enhance the effectiveness of munitions or mitigation. Where conventional platforms such as the tensile split Hopkinson bar can provide useful data on dynamic fracture, the time taken for the sample to reach an equilibrium state typically limits the sample size so that only a single fracture initiates
It is shown that this technique can drive large cylinders at radial strain rates of 104 s−1
Summary
The ability to predict the onset of fracture and the resulting fragmentation behaviour of a body is of huge importance to many fields in industry and engineering. The work presented here utilises a technique developed by the authors that facilitates expansion of cylinders using a gas gun where the temperature of the sample cylinder can be controlled prior to expansion [7, 8]. It is shown that this technique can drive large cylinders (dependant on barrel diameter) at radial strain rates of 104 s−1.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
