Blast wave time of arrival: A reliable metric to determine pressure and yield of high explosive detonations

The provision of robust and resilient blast protective systems requires detailed knowledge of the form and magnitude of blast loading that the structure is expected to protect against. Blast wave time of arrival is not typically required when assessing structural response to explosive loading and therefore is often overlooked in favour of other parameters such as peak pressure and impulse. However, well-known velocity-dependent relationships can be used to infer many different blast characteristics from arrival time measurements, offering key insights into the behaviour of a blast wave as it propagates. Furthermore, time of arrival can be quantified with higher precision and higher fidelity when compared to other loading parameters, as is shown in this article. Recent advancements in experimental techniques such as high speed video enable high-rate, full-field measurement of blast wave arrival time. This article reports a number of arrival time studies conducted by the author and colleagues. In particular, arena testing is used to make comments on the reliability of time of arrival measurements, and two recent examples are provided. In the first, arrival time measurements are used to infer near-field reflected blast pressure distributions, and in the second arrival time measurements are used to estimate the yield of the 2020 Beirut explosion. This article aims to demonstrate the versatility, accuracy, and importance of arrival time measurements, and the insights that such information can offer.