Abstract
The condition of dynamic stress equilibrium is not satisfied automatically when a split Hopkinson pressure bar (SHPB) is employed to determine the dynamic properties of soft materials. In order to develop guidelines for the proper design of SHPB experiments under valid testing conditions, an integrated experimental/analytical study has been conducted to examine the process of dynamic stress equilibrium in a soft rubber specimen. Dynamic compressive experiments on a RTV 630 and an ethylene-propylene-diene monomer rubber with a SHPB modified for soft material testing were conducted to determine the effects of specimen thickness and loading rate on the stress equilibrating process. An analytical model was employed to analyze the equilibrating processes observed in experiments. It is found that the incident loading rate dominates the initial non-equilibrium stress state, and the specimen thickness mainly affects the dynamic stress equilibrium after the initial stage.
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Song, B., Chen, W. Dynamic stress equilibration in split Hopkinson pressure bar tests on soft materials. Experimental Mechanics 44, 300–312 (2004). https://doi.org/10.1007/BF02427897
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DOI: https://doi.org/10.1007/BF02427897