Modeling the blast load induced by a close-in explosion considering cylindrical charge parameters

Structural damage is significantly influenced by the various parameters of a close-in explosion. To establish a close-in blast loading model for cylindrical charges according to these parameters, a series of field experiments and a systematic numerical analysis were conducted. A high-fidelity finite element model developed using AUTODYN was first validated using blast data collected from field tests conducted in this and previous studies. A quantitative analysis was then performed to determine the influence of the charge shape, aspect ratio (length to diameter), orientation, and detonation configuration on the characteristics and distributions of the blast loading (incident peak overpressure and impulse) according to scaled distance. The results revealed that the secondary peak overpressure generated by a cylindrical charge was mainly distributed along the axial direction and was smaller than the overpressure generated by an equivalent spherical charge. The effects of charge shape on the blast loading at 45° and 67.5° in the axial plane could be neglected at scaled distances greater than 2 m/kg 1/3 ; the effect of aspect ratios greater than 2 on the peak overpressure in the 90° (radial) direction could be neglected at all scaled distances; and double-end detonation increased the radial blast loading by up to 60% compared to single-end detonation. Finally, an empirical cylindrical charge blast loading model was developed considering the influences of charge aspect ratio, orientation, and detonation configuration. The results obtained in this study can serve as a reference for the design of blast tests using cylindrical charges and aid engineers in the design of blast-resistant structures.