Explosive Casing Voids for Predictable Fragmentation
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Solution Overview
Problem
Current explosive devices used to produce fragments suffer from unpredictability in fragment size, shape, and direction due to uneven casing breakup, and existing solutions that achieve desired fragment distribution are either expensive or time-consuming to manufacture.
Innovation Solution
An explosive device with a casing containing voids that define the fragments, allowing for predictable breakup and propulsion of fragments of various sizes and shapes when the explosive material is detonated, utilizing additive manufacturing and materials like stainless steel alloys or plastics, with voids that can be oriented in multiple directions to control fragment trajectory.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the casing is scored or notched on its inner surface to produce fragments, then fragment distribution is improved, but manufacturing precision deteriorates because the casing may not break along all notches predictably
Solution Approach 1:
The casing is divided into discrete fragments by incorporating voids that define specific fragment boundaries. This segmentation approach ensures predictable breakup into uniform fragments rather than relying on random cracking along score lines.
Solution Approach 2:
The fragment geometry is pre-defined by the void structure within the casing before detonation. The voids are strategically positioned to create predetermined fragment shapes and sizes, ensuring reliable and consistent fragment distribution upon breakup.
2Manufacturing precision
If preformed fragments are attached to the outside of a thin case using adhesive, then fragment distribution and configuration are improved, but device complexity increases due to multiple placement and quality control requirements
Solution Approach 1:
The fragment-defining voids are integrated directly into the casing structure as a single monolithic component. This merging of the fragment template and casing eliminates the need for separate fragment attachment processes, reducing manufacturing complexity while maintaining precise fragment configuration.
Solution Approach 2:
The casing structure itself serves as the fragment template through its internal void geometry. The casing automatically defines fragment shapes and positions through its own structure, eliminating the need for external fragment attachment and quality control processes.
3Ease of manufacture
If the casing breaks into uneven fragments, then manufacturing is simplified, but the effectiveness of the device deteriorates due to unpredictable fragment sizes, shapes, and directions
Solution Approach 1:
The casing incorporates localized void structures at specific positions to define uniform fragment geometry. This local modification of the casing structure ensures predictable fragment characteristics while maintaining overall casing integrity and manufacturability.
Solution Approach 2:
The void geometry parameters (size, shape, position) are optimized to produce uniform fragments with controlled dimensions. By adjusting these parameters, the device achieves reliable fragment effectiveness while maintaining ease of casing manufacturing.
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 solution enables the production of explosive devices with predictable fragment patterns and sizes, improving the effectiveness of munitions while simplifying manufacturing and reducing costs, as the casing can be made in a single piece using advanced manufacturing techniques.
Implementation Method 1
When the explosive material is detonated, the casing breaks into fragments along the voids within the casing
Implementation Method 2
the force of the explosive in a detonation
Data Source
AI summary
An explosive device, such as a munition or a part of a munition, has an explosive material surrounded by a casing that has one or more voids within the casing. The one or more voids define sizes and shapes of the fragments that the casing breaks into when the explosive material is detonated. The casing may be made using an additive manufacturing process, with the one or more voids fully between an inner surface of the casing and an outer surface of the casing. The voids may substantially define the size and shape of fragments making up a majority of the volume of the casing, such as 75% or more of the volume of the casing. The voids may change direction within the casing, for example branching and intersecting to define a plurality of rectangular (parallelepiped) or other shaped fragments.