Composite Multi-Lobe Barrel Stiffening Rods
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Solution Overview
Problem
Composite firearm barrels often lack the stiffness of conventional metal barrels, leading to reduced accuracy and increased muzzle displacement, while attempts to enhance stiffness through material substitution result in higher costs or compromised performance attributes.
Innovation Solution
Incorporating longitudinal stiffening rods into a composite winding overwrap around an inner liner to enhance axial stiffness, with a polymer matrix composite outer shell enclosing these rods, thereby increasing the percentage of 0° fibers and improving the barrel's structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If composite materials are used to reduce barrel weight, then weight is reduced, but axial stiffness decreases
Solution Approach 1:
The patent employs a hybrid composite structure combining carbon fiber reinforced polymer matrix composite (PMC) with aluminum alloy stiffening rods. The carbon fiber provides lightweight strength while the aluminum rods contribute axial stiffness, creating a composite system that achieves both weight reduction and maintained structural rigidity.
Solution Approach 2:
The stiffening rods are strategically positioned at specific locations along the barrel where axial stiffness is most needed, rather than uniformly distributing material throughout. This localized reinforcement approach maintains overall lightweight characteristics while providing targeted stiffness enhancement in critical areas.
2Strength
If barrel diameter and mass are increased to improve stiffness, then axial stiffness is improved, but weight increases
Solution Approach 1:
Instead of uniformly increasing barrel diameter and mass, the patent applies localized stiffening rods at specific positions along the barrel length. This provides the necessary axial stiffness enhancement only where needed, avoiding the penalty of overall weight increase associated with uniform dimensional increases.
Solution Approach 2:
The hybrid composite construction allows achieving required stiffness levels through material selection and strategic placement rather than increasing overall dimensions. The combination of carbon fiber PMC and aluminum alloy rods provides high stiffness-to-weight ratio, avoiding the weight penalty of conventional solid metal barrel increases.
3Weight of moving object
If conventional composite barrel designs are used, then weight is reduced, but manufacturing cost and complexity increase
Solution Approach 1:
The barrel is divided into distinct functional components: the carbon fiber PMC outer shell and the aluminum alloy stiffening rods. These segments can be manufactured separately using optimized processes for each material, then assembled together, reducing overall manufacturing complexity compared to attempting to create a monolithic composite structure.
Solution Approach 2:
The carbon fiber PMC shell acts as an intermediary bonding medium that connects and integrates the aluminum alloy stiffening rods with the barrel structure. This intermediary layer facilitates assembly and creates a unified structural system while allowing the use of different manufacturing processes for each component.
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 multi-lobe barrel design achieves improved axial stiffness, reducing muzzle displacement and maintaining light weight, thus enhancing accuracy and performance without the cost and performance sacrifices of prior solutions.
Implementation Method 1
a fiber reinforced polymer matrix composite incorporating longitudinal stiffening rods
Data Source
AI summary
A composite multi-lobe barrel is disclosed for directing the path of a dischargeable projectile. The multi-lobe barrel incorporates a plurality of longitudinal stiffening rods into a composite overwrap around an inner liner to enhance axial stiffness. The barrel is comprised of an inner liner defining an axial bore; a plurality of polymer matrix composite (PMC) stiffening rods equidistantly disposed around the inner liner and a PMC outer shell enclosing the stiffening rods. In one embodiment, a PMC inner wrap surrounds and is in direct contact with the inner liner, with the stiffening rods arranged equidistantly around the inner wrap, with this structure enclosed by a PMC outer shell.