Radial Slit Disc Assembly for Compact Crash Energy Attenuation

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Solution Overview

Problem

Current aircraft energy attenuation systems, such as wire bending mechanisms, are inefficient in dissipating energy during crash scenarios, leading to longer stroke lengths and higher weights, which can compromise occupant safety and vehicle stability.

Innovation Solution

A radial slit disc energy attenuation assembly that utilizes cyclic bending and unbending of stacked slit discs with a plunger having vertical grooves, converting kinetic energy into strain and frictional energy through plastic deformation of slit discs and spacer discs, thereby reducing stroke length and weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If wire bending mechanisms are used for energy attenuation, then energy absorption capability is achieved, but stroke length and weight increase

Engineering Contradiction:
Improveenergy dissipation efficiencyVSAvoidstroke length
Core Design Contradiction:
Loss of energyVSLength of moving object

Solution Approach 1:

The energy attenuation function is segmented into multiple thin disc components stacked together, each contributing to energy absorption through cyclic bending. This segmentation allows distributed energy dissipation across multiple elements, achieving high energy absorption efficiency while maintaining compact overall dimensions and reducing stroke length compared to single-element wire bending mechanisms.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The disc elements are designed to undergo dynamic cyclic bending and unbending during operation, transitioning from a static structure to a dynamic energy-dissipating system. This dynamic deformation behavior enables efficient energy absorption through material hysteresis while maintaining a compact form factor, resolving the contradiction between energy dissipation efficiency and stroke length.

Inventive Principle:
Principle #15Dynamics

2Loss of energy

If wire bending mechanisms are used for energy attenuation, then energy absorption capability is achieved, but weight increases

Engineering Contradiction:
Improveenergy dissipation efficiencyVSAvoidsystem weight
Core Design Contradiction:
Loss of energyVSWeight of moving object

Solution Approach 1:

The system is divided into multiple thin disc segments that can be stacked in configuration. This segmentation allows the use of lighter thin disc materials instead of heavier wire bending components, achieving comparable or superior energy absorption efficiency while significantly reducing overall system weight.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention employs thin disc elements that function as flexible shells, utilizing their bending stiffness and material properties for energy absorption. These thin disc components provide high energy absorption efficiency per unit weight, resolving the contradiction between energy dissipation efficiency and system weight.

Inventive Principle:
Principle #30Flexible shells and thin films

3Device complexity

If fixed profile energy attenuation systems are used, then structural simplicity is maintained, but energy dissipation efficiency decreases

Engineering Contradiction:
Improvesystem structure simplicityVSAvoidenergy dissipation efficiency
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The system incorporates dynamic cyclic bending of disc elements that automatically adjust to impact forces, transforming a static fixed-profile structure into a dynamic energy-dissipating system. This dynamic behavior enhances energy dissipation efficiency while maintaining relative structural simplicity through the straightforward stacked disc configuration.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The disc elements are designed with specific geometric parameters (radial slits, thickness, material properties) that optimize their bending characteristics and energy absorption capacity. By carefully selecting and adjusting these parameters, the system achieves high energy dissipation efficiency while maintaining a simple stacked disc structure, resolving the contradiction between structural simplicity and energy dissipation efficiency.

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

The radial slit disc energy attenuation assembly effectively dissipates energy during crashes, reducing stroke length and weight compared to traditional wire bender systems, enhancing safety and stability by efficiently converting kinetic energy into internal and frictional energy, while allowing for customizable stiffness for various occupant sizes.

Implementation Method 1

cyclic bending and unbending of a stacked arrangement of slit discs... through plastic deformation of slit discs and spacer discs, thereby reducing stroke length and weight

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Implementation Method 2

The kinetic energy of the plunger gets converted into strain energy and frictional interface energy, thereby attenuating the force realized during a crash scenario

Methodology Applied
Scientific EffectCyclic deformation: Hysteresis

Implementation Method 3

The kinetic energy of the plunger gets converted into strain energy and frictional interface energy, thereby attenuating the force realized during a crash scenario

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4011692B1Radial slit disc energy attenuation assembly
Publication Date: 2023.09.13 GOODRICH CORP
  • EP4011692B1 patent drawingFigure 1A
  • EP4011692B1 patent drawingFigure 1B
  • EP4011692B1 patent drawingFigure 2

AI summary

A radial slit disc energy attenuation assembly comprising: a slit disc stack (100) extending along a central axis, A, from a lower stack end to an upper stack end to define a stack height, the slit disc stack including a plurality of slit discs (108) and a plurality of spacer discs (110), the plurality of slit discs and the plurality of spacer discs vertically stacked in an alternating arrangement with respect to one another; and a plunger (102) extending from an upper end to a lower end, the lower end positioned proximate to the upper stack end and configured to penetrate the slit disc stack in response to receiving an applied force, wherein in response to penetrating the slit disc stack, energy is transferred to at least one deflected slit disc and is dissipated within the slit disc stack