Phase-Change Warhead Case for Selective Blast-Fragmentation Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional blast-frag warheads cause significant collateral damage due to metal fragments, limiting their use against targets in civilian populations, while eliminating fragments reduces the weapon's effectiveness against material and structural targets.
Innovation Solution
A warhead case made of meltable or phase-changeable material with a reactive energetic component allows for selective operation between blast and blast-frag modes by fragmenting in conventional mode and melting in blast-only mode, reducing collateral damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional blast-frag warhead is used, then the weapon effectiveness against material and structural targets is improved, but the collateral damage to civilian populations increases
Solution Approach 1:
The warhead case is designed with a phase-changeable material that can dynamically transition between solid and liquid states based on thermal activation. This dynamic property allows the same physical structure to serve dual functions: maintaining structural integrity for fragment formation in cold conditions, and becoming non-structural in hot conditions to suppress fragmentation. The phase transition temperature is specifically selected to enable this functional switching during weapon operation.
Solution Approach 2:
The invention changes the physical state parameter of the case material from solid to liquid through controlled heating. By altering the temperature parameter above the phase transition point, the case material transforms from a structural component that promotes fragmentation to a non-structural material that suppresses fragment formation. This parameter change allows the weapon to adapt its damage mechanism from blast-frag to blast-only mode.
2Object-affected harmful factors
If the metal case is replaced with fiber reinforced plastic to eliminate fragments, then the collateral damage is reduced, but the weapon effectiveness against material and structural targets decreases
Solution Approach 1:
The warhead case is designed to perform multiple functions depending on operational conditions. In cold conditions, it serves as a structural component that promotes fragmentation for enhanced effectiveness against material targets. In hot conditions, it serves as a non-structural component that suppresses fragmentation to reduce collateral damage. This multi-functionality is achieved through the phase-changeable material property and selective activation mechanisms.
Solution Approach 2:
Rather than using a fixed material composition, the invention employs a dynamic case structure that can switch between structural and non-structural states. The phase-changeable material allows the case to dynamically adjust its mechanical properties based on thermal conditions, enabling the weapon to adapt its fragment formation characteristics to match the operational requirements.
3Device complexity
If a single warhead design is used for all targets, then the logistic trail and mission loadout complexity is reduced, but the ability to address specific target vulnerabilities is limited
Solution Approach 1:
The warhead system is segmented into functionally distinct components: the explosive payload, the phase-changeable case material, and the reactive material for inducing phase change. This segmentation allows each component to be independently optimized while maintaining overall system versatility. The same basic warhead design can be adapted to different mission requirements by controlling the activation of the phase-change mechanism.
Solution Approach 2:
A single warhead design incorporates the capability to deliver both blast-frag and blast-only effects through the phase-changeable case mechanism. This universal design eliminates the need for separate weapon variants for different target types, simplifying logistics and training while maintaining the ability to address diverse target vulnerabilities including personnel, material, and structural targets.
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
Enables a single munition to effectively engage a broad target set with reduced collateral effects by selectively eliminating fragments, maintaining lethality while minimizing unintended damage.
Implementation Method 1
The heat released from the reactive material induces a phase transformation (e.g., melting) of the fragments within the case
Implementation Method 2
a reactive material capable of releasing sufficient thermal energy to melt the meltable material of the case
Data Source
AI summary
A munition includes a casing, the casing formed at least in part from a material comprising (i) a meltable or phase-changing material, and (ii) an energetic material; an explosive payload contained within the casing; and a fuze arrangement, the fuze arrangement comprising a main fuze configured and arranged to ignite the high explosive, and at least one secondary fuze configured and arranged to cause the casing material to melt or undergo a phase change. A method of selectively altering the mode of operation of a munition includes: forming a casing, the casing comprising a material comprising (i) a meltable or phase-changing material, and (ii) an energetic material; introducing an explosive payload into the casing; providing a fuze arrangement comprising a main fuse and at least one secondary fuze configured and arranged to cause the casing material to melt or undergo a phase change; and selectively activating the main fuze and the at least one secondary fuze in a manner that provided at least a first and a second mode of operation, the first mode of operation comprising blast coupled with fragmentation effects, and the second mode of operation comprising mainly blast effects.