Deep Rolling Forming Contoured Aircraft Panels

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional methods for forming contoured metal panels, such as shot peening and laser shock peening, suffer from process variability, environmental concerns due to shot disposal, and increased surface roughness, requiring additional costly treatments.

Innovation Solution

Deep rolling is used to form contoured structures by applying compressive forces with a deep rolling tool, which introduces plastic deformation to the metal work piece, allowing for the creation of convex contours without the need for expensive equipment or subsequent surface treatments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If shot peening is used to form contoured metal panels, then the metal panel develops concave curvature, but process variability increases and surface roughness increases

Engineering Contradiction:
Improvecontoured structureVSAvoidprocess variability
Core Design Contradiction:
ShapeVSManufacturing precision

Solution Approach 1:

The patent replaces the shot peening mechanical system with a deep rolling system that uses a controlled roller element to apply localized compressive forces. This substitution eliminates the stochastic nature of shot impact while maintaining the beneficial plastic deformation effects, thereby reducing process variability while achieving the desired contoured shape.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the fundamental parameter of the forming mechanism from discrete particle impact (shot peening) to continuous localized compression (deep rolling). By controlling the roller position, force magnitude, and traversal path, the process achieves precise control over the contoured structure formation while minimizing surface roughness increases.

Inventive Principle:
Principle #35Parameter changes

2Shape

If shot peening is used to form contoured metal panels, then the metal panel develops concave curvature, but surface roughness increases requiring additional surface treatment

Engineering Contradiction:
Improvecontoured structureVSAvoidsurface treatment requirements
Core Design Contradiction:
ShapeVSEase of manufacture

Solution Approach 1:

The deep rolling system replaces shot peening with a controlled roller that applies compression forces through a small contact area. This mechanical substitution inherently produces smoother surfaces compared to the chaotic impact of shot peening, thereby reducing or eliminating the need for additional surface treatment operations while still achieving the desired contoured geometry.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

By changing the forming mechanism from particle impact to localized roller compression, the patent fundamentally alters the surface interaction characteristics. The controlled contact pressure and continuous motion of the roller element produce more uniform plastic deformation with less surface disruption, thereby reducing surface roughness and subsequent treatment requirements.

Inventive Principle:
Principle #35Parameter changes

3Shape

If laser shock peening is used to form contoured metal panels, then the metal panel develops contoured structure, but equipment cost and process time increase

Engineering Contradiction:
Improvecontoured structureVSAvoidequipment cost
Core Design Contradiction:
ShapeVSDevice complexity

Solution Approach 1:

The patent replaces the complex laser shock peening system with a simpler deep rolling mechanism. By substituting high-energy laser equipment with a mechanically actuated roller system, the patent achieves comparable contoured structure formation while dramatically reducing equipment complexity and cost, along with eliminating time-consuming masking and unmasking operations.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the energy delivery mechanism from pulsed laser energy to controlled mechanical compression. This parameter change simplifies the overall system requirements, eliminating the need for expensive laser equipment, complex safety systems, and lengthy preparation steps, while still achieving effective plastic deformation for contour formation.

Inventive Principle:
Principle #35Parameter changes

4Strength

If shot peening uses small shots to impact the surface, then local low plastic deformation is introduced, but shot breaks and requires periodic replacement causing environmental problems

Engineering Contradiction:
Improveresidual compressive stressVSAvoidenvironmental concerns
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the shot peening system that uses consumable shots with a reusable deep rolling tool. This substitution eliminates the need for shot handling, storage, and disposal operations that create environmental concerns, while maintaining the ability to introduce beneficial residual compressive stresses through controlled localized plastic deformation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The deep rolling tool is a self-contained system that generates its own compressive force through mechanical actuation, eliminating the need for external shot supply systems and waste disposal infrastructure. The tool continuously applies controlled compression forces without consuming replaceable elements, thereby eliminating the environmental harm associated with shot lifecycle management.

Inventive Principle:
Principle #25Self-service

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

Deep rolling reduces process variability, minimizes surface roughness, and enhances fatigue strength, improving the efficiency and productivity of contour forming while avoiding the environmental issues associated with shot peening.

Implementation Method 1

The deep rolling tool applies a compressive force to the first side of the work piece. The deep rolling tool moves relative to the work piece while continuing to apply the compressive force to introduce plastic deformation to a first portion of the work piece.

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Implementation Method 2

The deep rolling tool applies a compressive force to the first side of the work piece. The another compressive force is applied to the second side of the work piece with a second deep rolling tool

Methodology Applied
Scientific EffectCompressive force: Compression

Implementation Method 3

a flow of metal, glass or ceramic shot impacts a surface of a metal work piece to elastically and plastically stretch that surface and introduce local low plastic deformation that manifests itself as a residual compressive stress

Methodology Applied
Scientific EffectResidual stress: Stress Relaxation

Data Source

PatentEP3162902B1Deep rolling forming
Publication Date: 2020.04.15 THE BOEING CO
  • EP3162902B1 patent drawingFigure 1A~1B
  • EP3162902B1 patent drawingFigure 2
  • EP3162902B1 patent drawingFigure 3A~3B

AI summary

Disclosed are a method and system to form a contoured structure using deep rolling. The method includes using deep rolling to introduce plastic deformation to one or more portions of a work piece to form a convex contour in the work piece. The work piece, and subsequently formed contoured structure, can be metal or composite. The disclosed deep rolling systems and methods form, for example contoured aircraft panels, while also providing fatigue strength improvement and low level of work hardening during the forming process rather than as a post-production surface treatment.