Double-Shell Explosive Charge for Enclosed Space Blast Control

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Solution Overview

Problem

Conventional high-explosive munitions cause significant collateral damage in urban environments, necessitating the development of more selective and efficient blast charges that can effectively target enclosed spaces while minimizing damage outside the immediate area of operation.

Innovation Solution

The production of compressible, double-shell explosive charges using granulated inorganic fuels, such as red phosphorus, combined with organic explosives and a binder system, which are processed into uniform granules for enhanced blast performance and reduced environmental impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional high-explosive munitions are used, then blast performance is achieved, but collateral damage increases

Engineering Contradiction:
Improvecollateral damageVSAvoidblast performance
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The explosive charge is designed with spatially differentiated properties: a central HE core for reliable blast initiation surrounded by a fuel-rich explosive mixture that provides enhanced pressure pulse in enclosed spaces. This local differentiation allows the charge to deliver maximum effect where needed (enclosed targets) while minimizing collateral damage in urban environments.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention uses a composite explosive structure combining conventional HE explosives (RDX, HMX, or CL-20) with inorganic fuels (aluminum powder, red phosphorus, or boron). This composite approach leverages the high fragment acceleration capacity of conventional HE while adding the pressure-enhancing effect of fuel-rich mixtures, achieving reliable blast performance with reduced collateral damage through optimized composition ratios.

Inventive Principle:
Principle #40Composite materials

2Reliability

If fuel-containing explosive mixtures are used, then blast performance is enhanced, but manufacturing complexity increases

Engineering Contradiction:
Improveblast performanceVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The explosive charge is segmented into two distinct functional zones: a central HE bursting core and an outer fuel-containing explosive mixture shell. This segmentation allows each component to be manufactured separately using optimized processes, then assembled together, reducing overall manufacturing complexity while maintaining enhanced blast performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention optimizes the oxygen balance parameter by adjusting the ratio of HE explosive to inorganic fuel within specific ranges (fuel content: 1-40 wt%, oxygen balance: -10% to +10%). This parameter optimization ensures reliable blast performance across different configurations while simplifying manufacturing by providing clear compositional guidelines.

Inventive Principle:
Principle #35Parameter changes

3Stress or pressure

If inorganic fuels are added to HE explosives, then pressure pulse is amplified, but mixture homogeneity becomes difficult to achieve

Engineering Contradiction:
Improvepressure pulseVSAvoidmixture homogeneity
Core Design Contradiction:
Stress or pressureVSManufacturing precision

Solution Approach 1:

The inorganic fuel is concentrated in the outer shell region rather than being uniformly distributed throughout the entire charge. This local concentration ensures high pressure pulse amplification in the fuel-rich zone while simplifying mixture preparation, as the HE core can be manufactured separately with standard homogeneity requirements.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention creates a composite structure where inorganic fuel particles are dispersed in the HE explosive matrix within the outer shell. This composite approach maintains mixture homogeneity through controlled dispersion while achieving pressure pulse amplification through the fuel-oxidizer reaction in the optimized composition zone.

Inventive Principle:
Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

These charges provide a cost-effective, efficient, and safer blast effect with reduced risk of collateral damage by amplifying pressure pulses in enclosed spaces, suitable for infantry applications like hand grenades and man-portable mortars, while avoiding the use of expensive or hard-to-source materials.

Implementation Method 1

The blast performance of explosive charges can usually be recorded in the form of the pressure pulse. An increase in the pressure impulse under given conditions (free field or enclosed space) can be achieved by increasing the peak pressure to be achieved

Methodology Applied
Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 2

A thermal, pressure-increasing effect for the RDX-Al system that can be derived from the explosion temperature of the reaction products can be found

Methodology Applied
Scientific EffectThermal energy release: Exothermic Reaction

Implementation Method 3

The blast performance of explosive charges can usually be recorded in the form of the pressure pulse

Methodology Applied
Scientific EffectPressure pulse: Shock Wave

Implementation Method 4

mixtures of inorganic fuels - plus, if necessary, inorganic oxidizing agents - in conjunction with organic explosives

Methodology Applied
Scientific EffectDeflagration: Deflagration

Data Source

PatentEP2580175B1Method for producing and using an explosive substance mixture containing fuel
Publication Date: 2017.07.05 RHEINMETALL WAFFE MUNITION GMBH
  • EP2580175B1 patent drawingFigure 1

AI summary

The invention relates to a method for producing a mechanical explosive substance mixture which is to be processed using pressing techniques and which consists of a granular fuel or a granular pyrotechnic mixture, a desensitised explosive agent and graphite. The method is safe, efficient, flexible and cost-effective and thus makes it possible to provide fuel-containing explosive substance mixtures in wide composition ranges for use in infantry ammunition such as hand grenades or ammunition for man-portable mortars. The granular fuel or granular pyrotechnic mixture is produced separately in a fluidised bed process or a multi-stage kneading, granulating and fabricating process, is fractionated to a grain size of 0.2 mm to 0.8 mm and, adding graphite, is then mixed mechanically with available grades of desensitised explosive agents and processed using pressing techniques.