Direct measurement of explosive impulse from contact to the ultra‐near field

Abstract

Measurement of impulse from explosive charges in contact and ultra‐near‐field regimes remains poorly characterised due to the short duration of loading, high strain rates, and the difficulty of obtaining direct momentum‐based measurements. Existing approaches are predominantly pressure‐derived or indirect, leading to uncertainty in the relationship between impulse, stand‐off distance and explosive properties in regimes where detonation products directly interact with the target. This paper presents direct measurements of explosive impulse across contact and ultra‐near‐field conditions obtained using a ballistic pendulum system. The measurements span a range of explosive types, charge masses and stand‐off distances, enabling systematic examination of impulse behaviour in regimes that are not well resolved in the open literature. The results demonstrate consistent and repeatable impulse measurements across the tested range and reveal clear relationships between impulse, stand‐off distance and net explosive quantity. In particular, the data highlights the transition from contact‐dominated loading to near‐field behaviour and identifies asymptotic trends in impulse as stand‐off increases within the geometric limits of the measurement system. Differences in behaviour between explosive types are also observed, indicating the influence of detonation characteristics on impulse delivery in the ultra‐near field. The findings provide a directly measured dataset for explosive impulse in contact and ultra‐near‐field regimes and contribute to improved understanding of momentum transfer under these conditions. The implications for scaling, experimental design and interpretation of near‐field explosive effects are discussed.