Flat-Surface Mandrel Layout for Composite Test Piece Collection

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Solution Overview

Problem

Existing methods for collecting test pieces from fiber-reinforced resin reinforcing layers result in curved shapes, making it difficult to handle flat plate-shaped test pieces for material property evaluation.

Innovation Solution

A mandrel with a cylinder portion and dome portions, each featuring multiple flat surface portions, is used to wind fiber-reinforced resin, allowing for the collection of flat plate-shaped test pieces from overlapping regions of the layered body.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the entire reinforcing layer is formed with a curved shape, then it can cover the liner of the high-pressure tank, but a test piece with a flat plate shape cannot be collected for easier handling and evaluation

Engineering Contradiction:

Improveease of handling test pieceVSAvoidshape of test piece

Core Design Contradiction:

Ease of operationVSShape

Solution Approach 1:

The mandrel is divided into multiple flat surface portions (first flat surface portions on the cylinder portion and second flat surface portions on the dome portions) among its total surface. By segmenting the mandrel surface into flat regions, the invention enables collection of flat plate-shaped test pieces from specific regions while maintaining the overall curved shape of the reinforcing layer for tank coverage.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the mandrel are given different surface properties: most of the mandrel maintains a curved shape for overall tank coverage, while specific localized regions (flat surface portions) are designed with flat surfaces to enable easy collection of flat plate-shaped test pieces. This local quality differentiation resolves the contradiction between overall curved shape and local flat test piece requirements.

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If the mandrel has an entirely curved surface, then it matches the liner shape for reinforcing layer application, but flat plate-shaped test pieces cannot be obtained for material property evaluation

Engineering Contradiction:

Improveshape accuracy of test pieceVSAvoidversatility of mandrel surface

Core Design Contradiction:

Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The mandrel surface is segmented into multiple flat surface portions distributed across the cylinder portion and dome portions. This segmentation allows specific regions to produce flat plate-shaped test pieces with high shape accuracy, while other regions maintain curved surfaces for adapting to the liner shape, thus resolving the contradiction between test piece precision and mandrel versatility.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The mandrel is designed with multi-functionality: it can serve as a form for creating the curved reinforcing layer that covers the liner, and simultaneously provide specific flat surface portions for producing flat plate-shaped test pieces. This universal design allows the single mandrel to fulfill multiple functions, resolving the contradiction between shape accuracy for testing and adaptability for manufacturing.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS12467587B2Mandrel and test piece collecting method for filament winding

Publication Date: 2025.11.11 HONDA MOTOR CO LTD

AI summary

A mandrel around which fiber-reinforced resin is wound, the mandrel including a cylinder portion having a plurality of first flat surface portions, and a pair of dome portions that are formed at respective ends of the cylinder portion and each include a plurality of second flat surface portions.