Incremental dynamic crack propagation of pipe subjected to internal gaseous detonation

•Relations of detonation load and its induced incremental crack growth were identified.•The effects of stress waves on high oscillating crack speeds were revealed.•Interval damages along crack paths were successfully captured and analyzed.•Dynamic fracture of pipe was modeled by progressive damage model and FSI approach. This paper aims to seek the fundamental and quantitative relationships between detonation load and its induced dynamic crack propagations of pipes. A progressive damage material model combined with fluid-structure coupling approach was presented to model the dynamic fracture of aluminum pipes due to internal gaseous detonation. The simulated pressure histories in pipe and typical fracture profiles were discussed and verified with experiments. The pipe responses, crack length histories and oscillating crack speeds were effectively obtained and analyzed in detail. Moreover, the interval damages along the crack path which corresponds to the incremental crack growth were successfully captured. It was concluded the crack propagations were strongly affected by the stress waves moving on the pipe. Then, a formula to calculate the oscillating frequencies of crack speeds was proposed and validated with the simulation results. Further, the quantitative relationship of detonation load speed, fundamental frequency of pipe, average crack speed and incremental crack growth distance was identified, which provides an in-depth understanding of crack propagations due to explosive load and can be useful for investigating pipe explosion accidents.