EV Rear Rail Transition Zone for Rear Crash Energy Absorption

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Solution Overview

Problem

The current rear rail design in electric vehicles, which lacks a fuel tank, is inadequate in absorbing excess crash energy, leading to potential kinetic energy transmission to the vehicle body and occupants, compromising safety.

Innovation Solution

A rear structure for electric vehicles with a transition zone made from a material having a specific fracture strain and critical bending angle, combined with geometric alterations and varying material properties, allowing controlled buckling and double bending deformation to optimize energy absorption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the rear rail design uses traditional fuel tank protection configuration, then fuel tank safety is improved, but energy absorption capacity deteriorates

Engineering Contradiction:

Improvefuel tank safetyVSAvoidenergy absorption capacity

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies local quality by making the transition zone with different material properties (higher ultimate tensile strength and thickness) compared to the rear portion. This localized enhancement creates an energy absorption mechanism through controlled buckling and double bending deformation, converting the harmful crash energy into beneficial deformation work while maintaining fuel tank protection.

Inventive Principle:

Principle #3Local quality

2Strength

If the rear structure transmits crash energy to the vehicle body, then structural integrity is improved, but occupant safety deteriorates

Engineering Contradiction:

Improvestructural integrityVSAvoidoccupant safety

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful crash energy into beneficial controlled deformation of the transition zone. The double bending deformation mechanism (upper and lower bends) transforms the kinetic energy from the rear collision into deformation work, absorbing the energy that would otherwise be transmitted to the vehicle body and occupants. This converts a harmful effect (energy transmission) into a beneficial one (energy absorption).

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 design effectively absorbs crash energy through controlled buckling and double bending deformation, ensuring passenger safety and protecting critical vehicle components like the battery pack.

Implementation Method 1

the rear portion absorbs energy during a rear collision, through controlled buckling for example

Methodology Applied

Scientific EffectControlled buckling deformation: Deformation

Implementation Method 2

absorb energy during a rear collision not only through the controlled buckling deformation of the rear section but also through the double bending deformation of the transition zone in its upper and lower bends

Methodology Applied

Scientific EffectBending deformation: Deformation

Data Source

PatentUS20250368264A1Rear Structure for an Electric Vehicle

Publication Date: 2025.12.04 ARCELORMITTAL SA

AI summary

Rear structure for an electric vehicle having a rear rail which includes a rear portion, a front portion and a transition zone, such that in the event of a rear crash the rear portion and the transition zone are both able to deform to maximize the amount of energy absorption.