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

Ning Jiang,Wen Bin Li,Da Cheng Gao,Wen Jin Yao,Letícia Fleck Fadel Miguel

doi:10.1155/2022/3144545

Ning Jiang, Wen Bin Li + Show 3 more

Open Access

https://doi.org/10.1155/2022/3144545

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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.

Highlights

A cylindrical charge warhead filled with fragments is a typical structure for warhead design and is called a fragmentation warhead [1]
Previous researchers have proposed a series of empirical formulas to estimate the performance of cylindrical charge warheads
√ where VGurney is the initial velocity of the fragment, 2E is the Gurney energy, and β is the ratio of charge mass to shell mass. e Gurney formula does not consider the sparse wave effect on the fragment’s velocity at the two ends of the warhead [4]

Summary

Introduction

A cylindrical charge warhead filled with fragments (e.g., metal balls) is a typical structure for warhead design and is called a fragmentation warhead [1]. Previous researchers have proposed a series of empirical formulas to estimate the performance of cylindrical charge warheads Among these formulas, the Gurney formula is representative in calculating the fragment’s velocity as follows [3]:. Erefore, Huang et al [4] proposed a more accurate formula to try to estimate the fragment’s velocity of a cylindrical shell detonated at one end as follows: VHuang 􏼐1 − 0.361 e− 1.111x/d􏼑 √ 􏽱 (2). Many experimental data have shown that the Taylor formula is inaccurate in predicting a fragment’s flying angle, especially for the fragments near the two ends of the warhead. In order to overcome the disadvantages in the models mentioned above, in terms of the impact of the axial sparse effect on the fragment dispersion distribution, this paper proposes a model to predict the dispersion distribution of the cylindrical warhead under one-end detonation by considering the axial sparse effect and the relative position along the shell’s axial direction. The theoretical model was validated by using static detonation tests

Samples and Experimental Layout

Experimental Results

Model Establishment

Test Verification to Validate the Model

Results and Discussion