Calculation Model of the Axial Dispersion Distribution of Cylindrical-Warhead Fragments

Abstract

The dispersion distribution characteristics of prefabricated fragments from an improvised explosive device (IED) are essential in defense technology development. To improve warhead design, it is essential to predict a fragment’s velocity and dispersion distribution accurately. This paper investigates a fragment’s flying angle from a detonated warhead with a cylindrical charge under a one-end central detonation. A modified formula for calculating the fragment dispersion distribution at each axial position of the warhead was obtained based on experimental data and model analysis. The impacts of the following parameters on the flying angle were considered in the formula: ratio of charge mass to shell mass, charge diameter, axial sparse effect, and relative axial shell position. The formula was verified by experimentation to be suitable for wide applications using different validation samples. Theoretical calculations with the formula show good accuracy in predicting the flying angle of cylindrical-shell fragments, agreeing with experimental data. The proposed model meets the error requirements of engineering applications. This work provides a theoretical foundation for subsequent research on damage effectiveness and IED damage assessment.

Functional Damage Assessment Method for Preformed Fragment Warheads to Evaluate the Effect on the Phased-Array Antenna

“…The initial fragment velocity and the spatial distributions of fragments enable the complete characterization of damage that a preformed fragment warhead can inflict [24]. Due to the axial sparsity, the fragment dispersion distribution at the ends of the cylindrical warhead with end-point initiation is not uniform [14]. A series of semi-empirical formulas have been previously proposed.…”

“…Calculation of Fragment Velocity Randers-Pehrson [8], Charron [9], Zulkoski [10], and Huang [12] et al proposed the formulas to predict the axial distribution of the initial fragment velocities when a cylindrical charge preformed fragment warhead detonates at the one-end central by modifying the Gurney velocity [6]. It was confirmed that Huang's formula was more accurate [14,15], which is expressed as…”

“…Since the lethality of the shockwaves decreases exponentially as the distance increases, and since it is difficult to quantitatively assess the damage caused by the shockwaves, our analysis of the damage of a low-yield preformed fragment warhead focused on the damage caused by fragments. Over the past 60 years, theoretical achievements of rapid calculation of the fragmentation field, including the fragment velocity and projection angle using semiempirical formulas derived from energy analysis, have been constantly evolving [6][7][8][9][10][11][12][13][14]. The reliability of the latest empirical formulas has been verified by a numerical simulation and an experimental study [15].…”

Dynamic Multiprojectile Attack and Killing Effects of Detonation Warheads

“…König [7] and Huang et al [8] studied a formula for the fragment dispersion angle of cylindrical warheads with end effects by experimental testing and numerical simulation. Jiang et al [9] studied the dispersion distribution of fragments under the charge of cylindrical shell during central initiation at one end. Wang et al [10] studied a calculation method of full-scale fragment distribution based on the CDEM method.…”