Controlled-Fragmentation Warhead With Surface-Contact Elements

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Solution Overview

Problem

Existing warheads struggle to achieve a bimodal effect against both semi-hard and soft targets while maintaining structural integrity during transport and firing.

Innovation Solution

A warhead design featuring preformed elements arranged with a surface contact against an inner shell, filled with a low-density filler material, and an inner shell with systematically arranged cupped recesses to control fragmentation, ensuring controlled fragmentation and high acceleration of elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If preformed elements are arranged in a warhead with gap contact against the inner shell, then the warhead can maintain structural integrity during transport, but the acceleration of elements upon detonation is reduced

Engineering Contradiction:
Improveacceleration of preformed elementsVSAvoidstructural integrity during transport
Core Design Contradiction:
SpeedVSStrength

Solution Approach 1:

The inner shell is designed with cupped recesses that create surface contact with preformed elements, forming a flexible yet supportive interface. This allows the structure to maintain integrity during transport while providing optimal contact for element acceleration during detonation

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The contact interface between the inner shell and preformed elements is changed from gap contact to surface contact through the cupped recess design. This parameter change optimizes both the structural integrity during transport and the acceleration efficiency upon detonation

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If a warhead is designed for controlled fragmentation, then the fragmentation pattern is predictable and controllable, but the adaptability against different target types is reduced

Engineering Contradiction:
Improveeffectiveness against different targetsVSAvoidwarhead structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The warhead employs two distinct fragmentation mechanisms: preformed elements for penetration against hard targets and controlled casing fragmentation for soft targets. This segmentation allows the warhead to deliver bimodal effects against different target types without requiring multiple separate warhead designs

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The warhead structure is designed to perform multiple functions: the inner shell with cupped recesses accelerates preformed elements for hard target penetration, while the outer casing is designed for controlled fragmentation to address soft targets. This multi-functionality achieves versatility against different target types within a single unified design

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Manufacturing precision

If preformed elements are arranged with surface contact against the inner shell, then the acceleration and penetration effect is improved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvecontact surface precisionVSAvoidmanufacturing difficulty
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The cupped recesses in the inner shell are pre-formed during manufacturing to provide the optimal contact surface geometry. This preliminary action ensures that when preformed elements are placed in the recesses, they achieve the desired surface contact configuration without requiring post-assembly adjustments or highly precise manual positioning

Inventive Principle:
Principle #10Preliminary action

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 design achieves effective penetration against both semi-hard and soft targets with controlled fragmentation, maintaining structural strength and compatibility with existing weapon systems.

Implementation Method 1

the inner shell is arranged for a controlled fragmentation upon a detonation of the explosive substance

Methodology Applied
Scientific EffectDetonation: Detonation

Implementation Method 2

filled with a low-density filler material

Methodology Applied
Scientific EffectEnergy absorption and distribution: Absorption (physical)

Data Source

PatentEP3721165B1warhead
Publication Date: 2025.12.24 BAE SYSTEM BOFORS AB
  • EP3721165B1 patent drawingFigure 1~2
  • EP3721165B1 patent drawingFigure 3a~3b
  • EP3721165B1 patent drawingFigure 4a~4b

AI summary

A warhead (1) comprises an outer casing (8) and an inner shell (7), which delimits a central space (5,6) for an explosive substance. The inner shell (7) receives a series of preformed elements (9), which are arranged in contact with the outer side of the inner shell (7). The inner shell (7) is arranged for a controlled fragmentation upon a detonation of the explosive substance. The preformed elements (9) are arranged with a surface contact against the inner shell (7).