Multi-bead Vehicle Door Beam Stiffness

Solution Overview

Problem

Current structural door beams for vehicles face a trade-off between stiffness and weight/cost, as increasing stiffness often results in higher mass and cost, making it challenging to meet fuel efficiency and cost reduction goals without compromising passenger safety.

Innovation Solution

A structural door beam design featuring a sheet metal strip with multiple beads and flanges, formed through a multi-stage cold forming process, which increases the peak-to-trough distance and height without compromising material quality, allowing for improved stiffness with minimal weight increase.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If reinforcement plates are welded to the beam and/or voids are filled with foam materials to improve stiffness, then the stiffness of the structural door beam is improved, but the weight and cost of the vehicle door increase

Engineering Contradiction:

ImprovestiffnessVSAvoidweight

Core Design Contradiction:

StrengthVSWeight of moving object

Solution Approach 1:

The beam cross-section is segmented into multiple regions with different heights, creating a multi-level structure that optimizes stiffness distribution. The profile includes a top region, middle region, and bottom region with varying heights to maximize bending resistance while minimizing material usage.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention transitions from a conventional two-dimensional flat or simple curved profile to a three-dimensional multi-level profile with varying heights in different regions. This dimensional complexity allows the beam to achieve higher stiffness-to-weight ratio by strategically placing material where it provides maximum structural benefit.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Strength

If reinforcement plates are welded to the beam and/or voids are filled with foam materials to improve stiffness, then the stiffness of the structural door beam is improved, but the cost of the vehicle door increases

Engineering Contradiction:

ImprovestiffnessVSAvoidcost

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The beam cross-section is segmented into multiple regions with different heights, creating a multi-level structure that optimizes stiffness distribution. The profile includes a top region, middle region, and bottom region with varying heights to maximize bending resistance while minimizing material usage.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention changes the geometric parameters of the beam profile, specifically the heights of different regions, to optimize stiffness. By varying the height parameter across different sections (top, middle, bottom regions), the beam achieves enhanced structural performance using the same base material without additional reinforcement components.

Inventive Principle:

Principle #35Parameter changes

3Strength

If the peak-to-trough distance and height are increased to improve stiffness, then the maximum force absorption and energy absorption are increased, but the weight of the beam increases

Engineering Contradiction:

Improveforce absorptionVSAvoidweight

Core Design Contradiction:

StrengthVSWeight of moving object

Solution Approach 1:

The beam cross-section is segmented into multiple regions with different heights, creating a multi-level structure that optimizes stiffness distribution. The profile includes a top region, middle region, and bottom region with varying heights to maximize bending resistance while minimizing material usage.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the beam profile are given different local qualities through varying heights. The top, middle, and bottom regions have optimized heights tailored to their specific structural requirements, allowing the beam to achieve maximum force absorption with minimal material in each zone.

Inventive Principle:

Principle #3Local quality

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 multi-bead design enhances the structural door beam's performance in side impact collisions by increasing the maximum force absorption and energy absorption by approximately 45% and 25% respectively, while maintaining a minimal weight increase, thus achieving improved safety without significant cost or weight penalties.

Implementation Method 1

formed through a multi-stage cold forming process, which increases the peak-to-trough distance and height without compromising material quality

Methodology Applied

Scientific EffectCold forming: Cold-forming

Data Source

PatentUS9566848B2Vehicle door reinforcing beam

Publication Date: 2017.02.14 MAGNA AUTOMOTIVE SERVICES

AI summary

A structural door beam for vehicles, and a method for making the same, is provided. The structural door beam has an elongate multiple channel structure defined by a central web of given thickness and known material composition, and includes end mounting-flanges integrally formed therewith. The elongate multiple channel structure comprises two outer channels separated one from the other in a lateral direction, and a third channel disposed between the two outer channels. The third channel defines a trough within the medial region between the two outer channels. A first one of the two outer channels is drawn to a peak of known height and the trough is drawn to a known depth, such that the trough to peak distance exceeds a maximum distance that is achievable in a single cold forming operation for the given thickness and material composition of the web.