Composite Sidemember Reinforcement with Longitudinal Undulations

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Solution Overview

Problem

Conventional motor vehicle passenger compartment sides made of steel or aluminum have high mass and limited energy absorption capacity during impacts, leading to early rupture under side impacts due to their material properties.

Innovation Solution

A passenger compartment side with an outer skin covering an inner lining, featuring a composite material outer spar reinforcement with undulations extending longitudinally, which can move perpendicular to the length of the reinforcement to absorb more energy before breaking, and an optional inner spar reinforcement made of composite material or hollow body fixed to the outer spar, enhancing impact resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If steel or aluminum is used for spar reinforcements, then high strength and large deformation capacity are achieved, but mass increases significantly

Engineering Contradiction:
Improveimpact resistanceVSAvoidmass of spar reinforcement
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent applies composite materials (fiberglass, carbon fiber, basalt fiber reinforced thermoplastic or thermosetting polymers) to replace traditional steel or aluminum spar reinforcements. This resolves the contradiction by providing sufficient strength and energy absorption capacity while significantly reducing the mass of the reinforcement structure.

Inventive Principle:
Principle #40Composite materials

2Weight of moving object

If composite material is used for spar reinforcement, then mass is reduced, but energy absorption capacity and deformation tolerance decrease

Engineering Contradiction:
Improvemass of spar reinforcementVSAvoidenergy absorption capacity
Core Design Contradiction:
Weight of moving objectVSStrength

Solution Approach 1:

The patent introduces undulations (curved波纹 structures) in the composite material wall of the outer spar reinforcement. These undulations extend in the longitudinal direction and can move perpendicular to the length during side impacts, enabling the composite material to absorb more energy through deformation before reaching the breaking point, thus resolving the contradiction between mass reduction and energy absorption capacity.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Strength

If composite material wall with undulations is used, then energy absorption before breaking is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveenergy absorption capacityVSAvoidmanufacturing complexity of corrugated structure
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent optimizes key parameters of the undulated structure including wall thickness, amplitude of undulations, and distance between undulations. These parameters are adapted according to the desired impact strength, allowing the design to achieve optimal energy absorption capacity while maintaining manufacturability through systematic parameter optimization rather than arbitrary design.

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 solution results in a lighter vehicle compartment side with improved resistance to lateral impacts by allowing greater energy absorption and delaying the rupture point, reducing intrusion of the center pillar and side doors during side impacts.

Implementation Method 1

the undulations can move in a direction perpendicular to the length of the side member reinforcement and thus absorb energy greater before reaching the breaking point

Methodology Applied
Scientific EffectEnergy absorption through deformation: Deformation

Data Source

PatentEP2877387B1Cabin side of a motor vehicle, of which the lower part comprises a sidemember reinforcement made from a composite material
Publication Date: 2016.09.21 PEUGEOT CITROEN AUTOMOBILES SA
  • EP2877387B1 patent drawingFigure 1~3
  • EP2877387B1 patent drawingFigure 4~6

AI summary

A cabin side of a motor vehicle comprising an outer skin that covers an inner lining, the latter comprising the lower part of the cabin side, an outer sidemember reinforcement (3) and an inner sidemember reinforcement (4), said two reinforcements (3, 4) extending between the two wheel arches, characterised in that the outer sidemember reinforcement (3) consists of a wall made from a composite material having multiple corrugations (7, 8, 9) that extend in the longitudinal direction of said outer sidemember reinforcement (3).