Passive Energy Absorber With Segmented Tubular Array

Solution Overview

Problem

Conventional energy absorbers in vehicles fail to meet various collision test requirements simultaneously, as the necessary stiffness for passing some tests leads to failure in others that require compliance and deformation.

Innovation Solution

An energy absorber comprising a container with relatively rigid tubular segments and a low-density soft foam spacer, where the tubular segments are arranged in a parallel array with the spacer facilitating their compression and displacement upon impact, allowing for adaptive deformation to absorb energy effectively across different impact scenarios.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional energy absorbers are designed with high stiffness to minimize axial deformation in low-velocity bumper impact tests, then they pass the low-velocity bumper impact test, but they fail to provide sufficient compliance and deformation in pedestrian leg impact tests

Engineering Contradiction:

ImprovestiffnessVSAvoidcompliance for different impact scenarios

Core Design Contradiction:

StrengthVSAdaptability or versatility

Solution Approach 1:

The energy absorber is divided into multiple tubular segments arranged in parallel within a container. Each tubular segment can deform independently upon impact, allowing the structure to provide both stiffness and compliance depending on the impact scenario. The segments are spaced apart to allow relative movement and deformation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The energy absorber transitions from a static rigid structure to a dynamic system where tubular segments can move and deform relative to each other. The segments are initially positioned to provide stiffness, but upon impact they can compress and relocate within the container, adapting to different impact forces and durations.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If conventional energy absorbers are designed with high compliance to allow deformation in pedestrian leg impact tests, then they pass the pedestrian leg impact test, but they fail to minimize axial deformation in low-velocity bumper impact tests

Engineering Contradiction:

Improvecompliance for different impact scenariosVSAvoidstiffness

Core Design Contradiction:

Adaptability or versatilityVSStrength

Solution Approach 1:

The energy absorber is divided into multiple tubular segments arranged in parallel within a container. Each tubular segment can deform independently upon impact, allowing the structure to provide both stiffness and compliance depending on the impact scenario. The segments are spaced apart to allow relative movement and deformation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The energy absorber transitions from a static rigid structure to a dynamic system where tubular segments can move and deform relative to each other. The segments are initially positioned to provide stiffness, but upon impact they can compress and relocate within the container, adapting to different impact forces and durations.

Inventive Principle:

Principle #15Dynamics

3Strength

If conventional energy absorbers use a single rigid structure to minimize vehicle front end damage in RCAR tests, then they pass the RCAR damageability test, but they fail to provide sufficient cushioning in pedestrian leg impact tests

Engineering Contradiction:

Improvestructural integrityVSAvoidimpact force on pedestrians

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The energy absorber is divided into multiple tubular segments arranged in parallel within a container. Each tubular segment can deform independently upon impact, allowing the structure to provide both stiffness and compliance depending on the impact scenario. The segments are spaced apart to allow relative movement and deformation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A foam spacer is introduced as an intermediary element between the tubular segments and the container walls. The foam spacer allows the segments to move and deform while providing cushioning and energy absorption, reducing the harmful impact forces transmitted to pedestrians.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Strength

If conventional energy absorbers use a single rigid structure to minimize axial deformation, then they protect rear structures from damage, but they cause greater leg injuries in pedestrian impacts due to insufficient deformation

Engineering Contradiction:

Improveprotection of rear structuresVSAvoidimpact force on pedestrian legs

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The energy absorber is divided into multiple tubular segments arranged in parallel within a container. Each tubular segment can deform independently upon impact, allowing the structure to provide both stiffness and compliance depending on the impact scenario. The segments are spaced apart to allow relative movement and deformation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A foam spacer is introduced as an intermediary element between the tubular segments and the container walls. The foam spacer allows the segments to move and deform while providing cushioning and energy absorption, reducing the harmful impact forces transmitted to pedestrians.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

The energy absorber achieves minimal deformation and effective energy absorption across a range of collision tests, including low-velocity bumper impacts, pedestrian leg impacts, and RCAR damageability tests, by optimizing the structure and spacing of tubular segments within the container, ensuring compliance and safety standards are met.

Implementation Method 1

The spacer is placed in the container with the tubular segments being arranged to be displaced within the container so that they compress the spacer when the impact force is received on the one side

Methodology Applied

Scientific EffectCompression: Compression

Implementation Method 2

The foam spacer may be a low density soft foam spacer assembled into the container that holds the tubular segments in place within the container

Methodology Applied

Scientific EffectDeformation: Deformation

Implementation Method 3

The tubular segments are relatively rigid and are assembled into the container in a parallel array with a cylindrical axis-C of the segments oriented perpendicular to the first direction

Methodology Applied

Scientific EffectDeformation: Deformation

Implementation Method 4

Passive energy absorbers are utilized in a wide variety of application on a vehicle to absorb the impact energy from a collision and manage crash energy

Methodology Applied

Scientific EffectEnergy absorption:

Data Source

PatentUS10131301B2Passive energy absorber structure adaptable to manage impact energy for different deformation targets and loads

Publication Date: 2018.11.20 FORD GLOBAL TECH LLC

AI summary

An energy absorber is disclosed that includes a container that receives a plurality of tubular segments and at least one spacer. The container includes one side that is adapted to receive an impact from a first direction. The tubular segments are assembled into the container in a parallel array with a cylindrical axis-C of the segments oriented perpendicular to the first direction. The spacer is placed in the container with the tubular segments being arranged to be displaced within the container so that they compress the spacer when the impact force is received on the one side. The method of making the energy absorber comprises assembling the plurality of tubular segments having in a container and assembling at least one spacer inside the container to hold the tubular segments in place.