Slotted Deformation Bullet Ogive for Uniform Expansion
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Solution Overview
Problem
Existing projectile technologies face challenges in achieving optimal deformation behavior when hitting gelatinous targets, especially with harder materials or those coated with textiles or gypsum concrete, due to issues with tool durability and uneven deformation caused by tension variations and material hardening during the deep drawing process.
Innovation Solution
A projectile intermediate is designed with a ductile cylindrical base body made from lead-free materials, featuring a slotted ogive section that allows for radial expansion and deformation without deep-drawing waves, using a punch-die arrangement for cold forming, where the slots create prongs that form a cavity with a smaller ogive tip opening, enabling penetration through harder materials and uniform deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a large ogive tip opening is used to allow gelatinous mass penetration, then deformation behavior is improved, but penetration through harder materials is prevented
Solution Approach 1:
The ogive wall is segmented into multiple notches that create discrete prongs or wall sections. These segmented structures allow the projectile to penetrate harder materials through the notches while the gelatinous mass enters through multiple smaller openings, maintaining both penetration capability and deformation behavior.
Solution Approach 2:
Different regions of the ogive structure are given different properties: the notched areas provide penetration paths for hard materials, while the overall cavity structure allows gelatinous mass entry. The wall thickness and notch geometry are locally optimized to balance penetration and deformation requirements.
2Ease of manufacture
If conical or pyramidal mandrels are used for deep drawing, then intermediate formation is achieved, but tool service life is reduced due to breaking
Solution Approach 1:
Instead of using a conical or pyramidal mandrel that concentrates stress at the tip, the invention uses a flat or slightly curved punch surface. The deformation is achieved by pressing the blank against a differently shaped die cavity, inverting the traditional mandrel-die arrangement to distribute stress more evenly and prevent tool breaking.
Solution Approach 2:
The punch geometry parameters are changed from sharp conical/pyramidal shapes to flatter surfaces with larger contact areas. This parameter change reduces stress concentration and increases tool service life while still achieving the desired intermediate formation through modified deep drawing processes.
3Ease of manufacture
If deep drawing with conical mandrel is used, then intermediate is formed, but external deep-drawing waves are created requiring complex post-processing
Solution Approach 1:
The deep drawing process is inverted by using a flat punch with a die cavity that has the desired final shape. This approach prevents the formation of external deep-drawing waves that occur with conical mandrels, as the material is pressed against a pre-formed cavity rather than being pushed by a pointed tool, eliminating the need for complex post-processing.
Solution Approach 2:
The die cavity is pre-formed with the exact shape needed for the final intermediate, including the ogive profile and cavity geometry. The blank is then pressed into this pre-prepared cavity, which guides the material flow and prevents wave formation during deformation, eliminating the need for subsequent corrective processing.
4Ease of manufacture
If stress variations and material hardening occur during deep drawing, then intermediate is formed, but uneven deformation occurs upon impact
Solution Approach 1:
The deep drawing parameters are changed to use lower pressures and larger contact areas, reducing material hardening and stress variations. The punch and die geometries are optimized to distribute deformation more uniformly across the blank, preventing localized hardening that would cause uneven deformation upon impact.
Solution Approach 2:
By inverting the deep drawing approach and using a flat punch with a shaped die cavity, the material flow is controlled more uniformly. This prevents the stress concentrations and localized hardening that occur with conical mandrels, resulting in more uniform deformation characteristics in the final intermediate product.
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 ensures optimized deformation behavior and penetration through harder materials, maintaining structural integrity and avoiding complex post-processing, while the slotted design prevents wave formation and ensures consistent deformation, even in standardized test procedures.
Implementation Method 1
The base body is cold-formed by pressing, in particular deep drawing, and in particular using a punch-die arrangement
Implementation Method 2
the gelatinous mass can enter the cavity to cause the desired deformation mentioned above
Data Source
Figure 1~4
Figure 1.1~4.1
Figure 5~8
AI summary
An intermediate for producing a projectile, more particularly a deformation bullet, consisting of a ductile blank that is cold-formed by means of pressing to form the intermediate, a cylindrical solid base end section and a press end section having a central press depression introduced by means of pressing and a wall delimiting the press depression to form an ogive-shaped tip, wherein the wall is formed with at least two slits extending in the axial direction of the intermediate, which slits separate at least two prongs in the circumferential direction of the intermediate, wherein the at least two slits extend by more than 10% of an axial total longitudinal extension of the intermediate from the wall end in the direction of the base end section.