Fiber-Reinforced Resin Composite Homogeneous Joint Strength

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The integration of simple-shape and complex-shape portions in fiber-reinforced resin composite materials often results in a phase boundary, which decreases the strength of the composite material due to differences in resin components used in each portion during Vacuum-assisted Resin Transfer Molding.

Innovation Solution

Using a benzoxazine resin composition for both the simple-shape and complex-shape portions, ensuring the resin components are the same, thereby eliminating the phase boundary and enhancing the material's strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If different resin components are used in simple-shape and complex-shape portions during Vacuum-assisted Resin Transfer Molding, then each portion can be optimized for its specific manufacturing requirements, but a phase boundary is formed at the joint face that decreases the strength of the composite material

Engineering Contradiction:
Improvemanufacturing flexibilityVSAvoidjoint face strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent applies homogeneity by using the same resin component (benzoxazine resin) in both the simple-shape outer panel and the complex-shape reinforcing portion. This ensures that the resin composition is uniform throughout the entire composite material, eliminating the formation of a phase boundary at the joint face and preventing the associated strength reduction.

Inventive Principle:
Principle #33Homogeneity

2Strength

If the same resin composition is used in both simple-shape and complex-shape portions, then a phase boundary is eliminated and strength is improved, but the ability to optimize each portion for specific manufacturing requirements is reduced

Engineering Contradiction:
Improvejoint face strengthVSAvoidresin optimization flexibility
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The patent employs parameter changes by utilizing the unique properties of benzoxazine resin, specifically its ability to undergo ring-opening polymerization. This chemical characteristic allows the resin to maintain uniform composition throughout the composite material while still enabling effective impregnation of fibers in both simple-shape and complex-shape portions, thus achieving both strength improvement and manufacturing adaptability.

Inventive Principle:
Principle #35Parameter changes

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

This approach suppresses the strength decrease at the joint face of simple-shape and complex-shape portions, resulting in improved interlaminar shear and four-point flexural strengths of the composite material.

Implementation Method 1

it has gradually come to light by experimentation that ring-opening polymerization of a benzoxazine ring(s) gives a composite material excellent in both toughness and fire retardancy

Methodology Applied
Scientific EffectRing-opening polymerization: Chemical Bonding

Data Source

PatentEP2762520B1Fiber-reinforced resin composite material and process for producing same
Publication Date: 2020.11.11 SUBARU CORP
  • EP2762520B1 patent drawingFigure 1
  • EP2762520B1 patent drawingFigure 2
  • EP2762520B1 patent drawingFigure 3

AI summary

The purpose of the present invention is to inhibit a decrease in strength attribute to the interface between a simple-shape portion and a complicated-shape portion. This fiber-reinforced resin composite material comprises: a simple-shape portion formed from at least one sheet-shaped prepreg material obtained by impregnating reinforcing fibers with a resin; and a complicated-shape portion obtained by impregnating reinforcing fibers with a resin, the complicated-shape portion having been integrated with the simple-shape portion. The resin used for the preprg material comprised the same components as the resin used for the complicated-shape portion.