Composite Impact Indicators for Barely Visible Damage Detection

Solution Overview

Problem

Detecting Barely Visible Impact Damage (BVID) in fibre-reinforced polymer components is difficult due to internal damage being confined to the reverse side, leading to unexpected failures and increased material and weight costs to prevent such damage.

Innovation Solution

Incorporating raised features made of non-reinforced polymer on the surface of fibre-reinforced polymer components, which are more fragile and provide a visual indication of impacts above a predetermined threshold, allowing early detection of damage without requiring thorough inspections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If composite components are strengthened or reinforced to withstand impacts below BVID threshold, then reliability is improved, but weight and material cost increase

Engineering Contradiction:

Improveimpact resistanceVSAvoidcomponent weight

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent applies local quality by incorporating fibre-reinforced polymer only in specific critical regions where impact damage is most likely to occur and be hardest to detect, rather than uniformly throughout the entire component. This allows the component to have enhanced reliability at critical locations while maintaining lower overall weight.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent utilizes composite materials by combining fibre-reinforced polymer regions with non-reinforced polymer regions within the same component. The fibre-reinforced regions provide impact resistance and damage detection capability, while the non-reinforced regions reduce overall weight, creating an optimized composite structure.

Inventive Principle:

Principle #40Composite materials

2Reliability

If composite components are strengthened or reinforced to withstand impacts below BVID threshold, then reliability is improved, but material cost increases

Engineering Contradiction:

Improveimpact resistanceVSAvoidmaterial cost

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies local quality by incorporating fibre-reinforced polymer only in specific critical regions where impact damage is most likely to occur and be hardest to detect, rather than uniformly throughout the entire component. This allows the component to have enhanced reliability at critical locations while maintaining lower overall weight.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent utilizes composite materials by combining fibre-reinforced polymer regions with non-reinforced polymer regions within the same component. The fibre-reinforced regions provide impact resistance and damage detection capability, while the non-reinforced regions reduce overall weight, creating an optimized composite structure.

Inventive Principle:

Principle #40Composite materials

3Measurement precision

If visual inspection of reverse side or internal surfaces is performed to detect BVID, then detection precision is improved, but time consumption increases

Engineering Contradiction:

Improvedamage detection precisionVSAvoidinspection time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies color changes by incorporating contrasting visual features (such as coloured fibres or visual indicators) in the fibre-reinforced polymer regions. When impact damage occurs, these visual features change or become visible, providing immediate visual indication of damage location and severity, thereby improving detection precision while reducing inspection time.

Inventive Principle:

Principle #32Color changes

Solution Approach 2:

The patent applies segmentation by dividing the component into distinct fibre-reinforced polymer regions and non-reinforced polymer regions. The fibre-reinforced regions act as dedicated damage detection zones with visible indicators, allowing inspectors to focus only on these specific segments rather than conducting exhaustive inspections of the entire component surface.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentEP3575071B1Composite components

Publication Date: 2025.09.17 CROMPTON TECH GROUP

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AI summary

A fibre-reinforced polymer component 202 is provided which comprises a main portion 204 comprising fibre-reinforced polymer and at least one surface and at least one raised feature 206 extending from said surface. The at least one raised feature 206 consists of non-reinforced polymer and is shaped to incur visually perceptible damage when the component 202 is subject to an impact with an energy above a predetermined impact energy threshold and to resist an impact with an energy below the predetermined impact energy threshold. The at least one raised 206 feature thus provides a clear visual aid as to when a component 202 has experienced an impact with an energy above the impact energy threshold. Because the raised feature 206 consists of polymer without fibre reinforcement, it is more fragile than the fibre-reinforced polymer main portion 204 and thus reduces the energy at which impacts may be detected.