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Detailed knowledge of the dynamic viscoelastic properties of bone is required to understand the mechanisms of macroscopic bone fracture in humans, and other terrestrial mammals, during impact loading events (e.g. falls, vehicle accidents, etc.). While the dynamic response of bone has been studied for several decades, high-quality data remain limited, and it is only within the last decade that techniques for conducting dynamic compression tests on bone at near-constant strain rates have been developed. Furthermore, there appears to be a lack of published bone data in the intermediate strain rate (ISR) range (i.e. 1–100 s −1 ), which represents a regime in which many dynamic bone fractures occur. In this paper, preliminary results for the dynamic compression of bovine cortical bone in the ISR regime are presented. The results are obtained using two Hopkinson-bar-related techniques, namely the conventional split Hopkinson bar arrangement incorporating a novel cone-in-tube striker design, and the recently developed wedge bar apparatus. The experimental results show a rapid transition in the strain rate sensitive behaviour of bovine cortical bone in the ISR range. Finally, a new viscoelastic model is proposed that captures the observed transition behaviour.

This is a repository copy of Behaviour of a blast-driven ball bearing embedded in rear detonated cylindrical explosive.

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A series of laboratory-scale blast characterization experiments are presented to show the degree to which two alternative configurations of an instrumented ballistic pendulum can provide an ideal impulsive load. Both the total impulses and blast pressure histories were captured, the latter using a centrally mounted Hopkinson bar. Repeatable and consistent total impulse values were achieved, while the Hopkinson bar technique was sufficient to capture the essential shape of the blast loads, although the fine detail of the peak pressure could not be resolved due to higher mode dispersion. A short stand-off configuration produced short duration blast loads that approached an ideal impulsive load condition with near uniform impulse distributions, although the blast pressure distributions were non-uniform. Conversely, a blast tube configuration produced blast loads with near uniform pressure and impulse distributions but did not approach an ideal impulsive load condition, that is, the pressure history must be accounted for in subsequent analytical work.