Braided Trigger Element in Fiber Composite Crash Energy Dissipation

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Solution Overview

Problem

Existing energy absorption systems in crash load cases, particularly those using fiber-reinforced plastics, face challenges in achieving high energy absorption characteristics while ensuring structural integration and connection to vehicle support structures, often resulting in suboptimal performance and material utilization.

Innovation Solution

The integration of a braided trigger element within the fiber composite component allows for direct contact and defined failure behavior, enabling high energy absorption while also facilitating integration into vehicle support structures using common connection technologies like screws or rivets, thereby optimizing energy absorption and structural integration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If common measures like component rejuvenation or targeted omission of fibers are used to initiate energy-absorbing failure behavior with structural integration, then structural integration is improved, but energy absorption characteristic values are reduced

Engineering Contradiction:

Improvestructural integrationVSAvoidenergy absorption characteristic values

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-forming a chamfer trigger element during the composite component manufacturing process. This trigger element is integrated into the component structure before use, creating a predefined stress concentration zone that will initiate controlled delamination during crash events. The trigger element is positioned and shaped in advance to ensure optimal energy absorption performance while maintaining structural integration capabilities.

Inventive Principle:

Principle #10Preliminary action

2Adaptability or versatility

If FRP pipe is turned inside out with corresponding upstream component to achieve energy-absorbing failure mode, then structural integration is improved, but energy absorption characteristic values are reduced

Engineering Contradiction:

Improvestructural integrationVSAvoidenergy absorption characteristic values

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

3Reliability

If the entire length of fiber composite component is used for energy absorption, then energy absorption capability is improved, but connection to supporting structure is limited

Engineering Contradiction:

Improveenergy absorption capabilityVSAvoidconnection capability

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies segmentation by dividing the fiber composite component into distinct functional zones: trigger elements at the ends for initiating failure, intermediate sections for energy absorption through delamination, and flanged end sections for structural connection. This segmentation allows different portions of the component to perform specialized functions, maximizing both energy absorption capability and connection versatility.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies multi-functionality by designing flanged end sections that serve dual purposes: providing connection interfaces for structural integration and acting as boundaries for the energy absorption zone. The flanges enable the component to be connected to various supporting structures while the intermediate sections maintain full-length energy absorption capability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

4Reliability

If trigger element is integrated directly into fiber composite component, then energy absorption is improved, but manufacturing complexity increases

Engineering Contradiction:

Improveenergy absorption performanceVSAvoidmanufacturing complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by pre-forming the chamfer trigger element during the composite component manufacturing process itself, rather than adding it as a separate post-processing step. The trigger element is created as an integral part of the mold or tooling used to manufacture the composite component, which initiates the energy-absorbing delamination behavior during crash events.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent applies merging by combining the trigger element and the fiber composite component into a single integrated structure. The trigger element is embedded within the composite material during manufacturing, eliminating the need for separate assembly steps and reducing overall manufacturing complexity despite the added functional capability.

Inventive Principle:

Principle #5Merging (Combining)

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 achieves nearly ideal energy absorption with high specific characteristic values, allowing for efficient use of the entire fiber composite component and enabling material-independent joining, while regulating energy absorption levels and maximum force through the shape of the trigger element.

Implementation Method 1

converting kinetic energy into deformation energy, which occurs in the event of a crash or a collision of vehicles

Methodology Applied

Scientific EffectEnergy absorption through deformation: Deformation

Implementation Method 2

An initiation of the energy-absorbing failure behavior of the fiber composite component is achieved by means of a defined weakening (triggering), for example by reducing the wall thickness at one end of the component. This causes an increase in stress under pressure, which ultimately leads to a targeted and defined failure behavior

Methodology Applied

Scientific EffectStress concentration:

Implementation Method 3

The fracture front that forms is characterized by delaminations and fiber fractures and is largely responsible for the high level of energy absorption

Methodology Applied

Scientific EffectFracture mechanics: Fracture Mechanics

Data Source

PatentEP2407685B1Device for dissipating energy in a crash load case and support structure for a vehicle

Publication Date: 2019.04.17 AUDI AG

Figure 1

AI summary

The invention relates to a device for energy dissipation in a crash load case with at least one trigger element (24a, 24b) and a fiber composite component (30), wherein the at least one trigger element (24a, 24b) influences the failure behavior of the fiber composite component (30) in a defined manner during the crash load case, and to a supporting structure for a vehicle with at least one such device. According to the invention, the fiber composite component (30) has a braided fiber composite (32) in which the at least one trigger element (24a, 24b) is woven such that there is direct contact between the at least one trigger element (24a, 24b) and the fiber composite (32).