Experimental and numerical investigation on the attenuation of blast waves in concrete induced by cylindrical charge explosion

Concrete material is widely used in military facilities to resist the deliberate attacks by earth penetration weapon (EPW). The charge of EPW is more nearly cylindrical than spherical in geometry, and its explosion usually occurs in a certain depth of burial (DoB). To quantify the influences of charge shape and DoB on blast waves in concrete, experimental and numerical investigation on the attenuation of blast waves in concrete induced by cylindrical charge explosion is carried out in the present study. Firstly, a set of blast wave test in concrete with cylindrical charges is conducted to provide fundamental data including the stress-time histories and failure in concrete with the considerations of aspect ratio and DoB. Then based on the concrete material model by Kong and Fang and LS-DYNA's multi-material ALE algorithm, the attenuation of free-field blast waves in concrete generated from spherical charges and cylindrical charges with different aspect ratios is numerically investigated in detail. Finally, the influence of DoB on the peak stress directly below cylindrical charges is discussed and a coupling factor for peak stress is proposed. Several empirical formulas are presented based on dimensional analysis and curve-fitting the numerical data, including the critical distance beyond which the charge shape effect could be neglected, coupling factor for peak stress and peak stress from cylindrical charges with varied aspect ratio under different DoBs, all of which are useful for blast-resistant design.

Automated summary

This study investigates the attenuation of blast waves in concrete induced by cylindrical charge explosions through experimental and numerical research. The effects of charge geometry and burial depth on blast waves are quantified, and empirical formulas are proposed for blast-resistant design. The results provide valuable data and insights for understanding and mitigating the impact of explosive attacks on military facilities.