Modeling dynamic fragmentation of concrete under high strain-rate loading

Extreme high-rate loading conditions in structural materials trigger a complex process of fragmentation involving probabilistic, energetic and mechanical aspects. In this work we discuss a one-dimensional model based on [1] that captures the physics of dynamic fracture and fragmentation in concrete at strain rates from 103 to 105 /s, with particular interest in the higher strain rate values. In particular, the model considers a one-dimensional bar under a uniform tensile initial strain rate, with a stochastically varying strength. Initial results for the relationship between average fragment size and strain rate show good agreement with shock tube experiments on concrete panels. However, the predicted distribution of fragment size exhibits a smaller variance than that observed in the experiments. Future work will evaluate this difference in the results, which could be the result of the one-dimensionality of the model, heterogeneity of strain rate in the shock tube tests, experimental measurement errors, or a combination of all of these. Further investigations to extend the present model to other brittle materials like glass and concrete are also currently under development.