Composite-Frame Propellant Tank With Integrated Y-Joint Reinforcement

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Solution Overview

Problem

Conventional cryogenic projectile propellant tanks face issues with lengthy processing times, high costs, safety risks for operators, and structural weaknesses at the Y-joint portion, along with inadequate prevention of content fluctuation during propulsion.

Innovation Solution

A composite inner frame multi-bonded barrel is manufactured with a baffle structure and a softening strip integrated into the Y-joint portion, using a method that involves pre-bonding multiple frames and a shell-integrated design to enhance bonding strength and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If 24 segments are bonded after manufacturing, then the tank can be assembled, but the process becomes complex, airtightness is compromised, and recovery is difficult

Engineering Contradiction:
Improveassembly processVSAvoidnumber of bonded parts
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The barrel is divided into multiple segments (24 segments) that are manufactured separately and then bonded together. This segmentation allows for easier manufacturing of individual segments, simplified mold design, and modular assembly, while the bonding process creates a unified structure that maintains airtightness.

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If the mold is removed after assembling the skirt-barrel, then the assembly can be completed, but the process becomes difficult, time-consuming, and creates safety risks for operators

Engineering Contradiction:
Improvemold removal processVSAvoidprocessing time
Core Design Contradiction:
Ease of manufactureVSLoss of time

Solution Approach 1:

The skirt is detached from the barrel before the mold removal process. This preliminary action allows the mold to be removed more easily and safely without the constraint of the assembled skirt-barrel structure, eliminating the need for operators to enter the assembly interior and significantly reducing processing time and safety risks.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If a Y-shaped gap is formed at the Y-joint portion, then the skirt-barrel assembly is complete, but stress concentration occurs and the structure becomes vulnerable

Engineering Contradiction:
Improveassembly structureVSAvoidY-joint portion strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

A softening strip is added specifically at the Y-joint portion where the skirt meets the barrel. This localized modification addresses the stress concentration problem at this critical location without changing the overall assembly structure. The softening strip distributes stress more evenly, preventing stress concentration and enhancing the structural integrity of the vulnerable Y-joint area.

Inventive Principle:
Principle #3Local quality

4Strength

If a triangular softening strip and short insert are inserted into the skirt-barrel assembly, then the Y-joint weakness is solved, but processing time increases, cost increases, and defects are more likely

Engineering Contradiction:
ImproveY-joint portion strengthVSAvoidmanufacturing efficiency
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The softening strip is integrated into the barrel manufacturing process itself, rather than being inserted separately into the assembled skirt-barrel. This merging of operations eliminates the need for additional insertion steps, reducing processing time and the number of bonding operations. By combining the softening strip formation with the barrel manufacturing, the solution maintains Y-joint strength while improving manufacturing efficiency and reducing defect risks.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4043716B1Inner composite frame multi-joined barrel, shell-integrated projectile propellant tank including same, and method for manufacturing same
Publication Date: 2025.08.06 ANH STRUCTURE CO LTD
  • EP4043716B1 patent drawingFigure 1
  • EP4043716B1 patent drawingFigure 2
  • EP4043716B1 patent drawingFigure 3A~3B

AI summary

Provided is a composite inner frame multi-bonded barrel, a shell-integrated projectile propellant tank including the same, and a method for manufacturing the barrel and the tank. The shell-integrated projectile propellant tank may include the composite inner frame multi-bonded barrel including a cylinder portion including a plurality of inner frames bonded together; a dome portion including an upper dome frame and a lower dome frame bonded to an upper end and a lower end of the cylinder portion, respectively; a cylindrical shell coated on an outside of the composite inner frame multi-bonded barrel; and at least one manhole cover sealing a manhole cover coupling hole formed in a center of the upper dome frame or the lower door frame, and the at least one manhole cover has a fluid injection port formed on one side thereof.