MCD Shell Asymmetric Fragmentation Design

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Solution Overview

Problem

Conventional explosive-filled, fragmentation shells disperse fragments in all directions, posing risks to personnel and materiel in civilian environments and close combat situations, where controlled fragment dispersal towards a target is necessary to minimize collateral damage.

Innovation Solution

A method and design for modifying or producing shells with a rear insert thickening, typically made of combustible materials like aluminum, to retard rearward fragments and ensure forward and lateral dispersal, using pre-programmed detonation and sensors to control the fragment pattern.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional fragmentation shells disperse fragments in all directions, then the shells can effectively engage hostile targets, but they pose risks to personnel and materiel in civilian environments and close combat situations

Engineering Contradiction:
Improveeffectiveness against hostile targetsVSAvoidcollateral damage to civilians and friendly forces
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The shell design introduces asymmetric fragment dispersal characteristics by shaping the shell body and positioning the explosive charge to create a preferred fragmentation direction forward and laterally, while minimizing rearward fragment dispersal. This asymmetric geometry allows the shell to maintain effectiveness against targets while reducing harmful effects to civilians and friendly forces in the rear area.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

Different regions of the shell are designed with different properties: the forward and lateral portions are optimized for fragment dispersal toward targets, while the rear portion is modified to reduce fragment generation in that direction. This local differentiation of fragment dispersal characteristics allows selective engagement of targets while protecting vulnerable areas.

Inventive Principle:
Principle #3Local quality

2Productivity

If fragmentation shells are used in urban environments and close combat, then hostile targets can be engaged, but friendly forces and civilians may be injured by rearward dispersing fragments

Engineering Contradiction:
Improveability to engage targets in close quartersVSAvoidinjury risk to friendly forces
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The shell employs asymmetric design features including a shaped forward portion and modified rear structure that direct fragment dispersal forward and laterally while suppressing rearward fragmentation. This allows the shell to be used effectively in close-quarters urban combat without exposing friendly forces to dangerous rearward-flying fragments.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The design converts what would normally be a harmful rearward fragment dispersal pattern into a beneficial forward and lateral dispersal pattern through strategic placement of the explosive charge and shaping of the shell body, thereby protecting friendly forces while maintaining combat effectiveness.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Object-affected harmful factors

If shells are designed to disperse fragments only forward and laterally, then collateral damage is reduced, but the shell structure becomes more complex

Engineering Contradiction:
Improvecollateral damage reductionVSAvoidshell structure complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

Rather than redesigning the entire shell structure, the invention applies localized modifications to specific regions of the shell body and explosive charge positioning. These targeted local changes achieve the desired directional fragment dispersal pattern without requiring complete structural redesign, thereby limiting the increase in overall complexity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The shell incorporates asymmetric shaping of the body and strategic positioning of the explosive charge to achieve directional fragment dispersal. This asymmetric design, while departing from conventional symmetric shell structures, uses relatively simple geometric modifications rather than complex mechanical systems to control fragment patterns.

Inventive Principle:
Principle #4Asymmetry

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

The modified shells significantly reduce rearward fragment dispersal, allowing for safe engagement of targets near civilians and friendly forces by directing fragments forward and laterally, minimizing collateral damage and enabling use in urban environments and close-range combat.

Implementation Method 1

disperse fragments on the pre-programmed detonation of their own explosive

Methodology Applied
Scientific EffectDetonation: Detonation

Implementation Method 2

when the shell bursts normally give rise to fragments directed rearwards

Methodology Applied
Scientific EffectPressure wave: Shock Wave

Implementation Method 3

thickening of those parts of the body of the shell which would otherwise normally have given rise to fragments directed rearwards

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 4

retard fragments in rearward directions formed from the rear part of the shell body

Methodology Applied
Scientific EffectMaterial resistance: Friction

Data Source

PatentEP1952087B1MCD shell
Publication Date: 2016.06.29 BAE SYSTEM BOFORS AB
  • EP1952087B1 patent drawingFigure 1~2
  • EP1952087B1 patent drawingFigure 3

AI summary

The present invention relates to a method for firing explosive-filled, fragmentation shells (1) that disperse fragments on the pre-programmed detonation of their own explosive (7) so as to reduce the risk of accidental injury to unprotected personnel and damage to materiel, which at the moment of firing are undeservedly situated between the firing weapon and the target. The invention also encompasses shells (1) produced or modified according to said method.