Stationary Mandrel AFP for Barrel Composite Layup

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Solution Overview

Problem

Existing methods for laying up barrel-shaped composite structures, such as aircraft fuselage sections, rely on massive and costly rotating mandrels, limiting laydown speed and production efficiency due to the need for substantial tooling and support systems.

Innovation Solution

A method and apparatus that apply composite material to a stationary outer mold line (OML) using an automatic fiber placement (AFP) head and a parallel kinematic machine (PKM) manipulator, allowing continuous layup without rotating the mandrel, reducing tooling costs and increasing production efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a massive rotating mandrel is used to apply composite material, then the structure can be formed on the mandrel surface, but the mandrel mass increases leading to reduced layup speed and production efficiency

Engineering Contradiction:

Improvesurface formation accuracyVSAvoidlayup speed

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The patent inverts the conventional approach by applying composite material to the interior surface of the mandrel rather than the exterior surface. This allows the mandrel to remain stationary while the AFP head rotates around it, eliminating the need for a massive rotating mandrel and enabling higher layup speeds without compromising surface formation accuracy

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent replaces the mechanical rotation of a massive mandrel with a rotating AFP head on a lighter mandrel. This substitution reduces the rotating mass significantly, allowing faster rotation speeds and improved productivity while maintaining the required manufacturing precision through controlled AFP head motion

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If a massive self-supporting mandrel is used, then the mandrel can react forces and decelerations, but the mandrel mass increases requiring substantial foundations and large motors

Engineering Contradiction:

Improveforce reaction capabilityVSAvoidmandrel mass

Core Design Contradiction:

ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent extracts the rotation function from the mandrel and transfers it to the AFP head. The mandrel becomes a stationary support structure that only needs to provide geometric accuracy, while the rotation and composite application are performed by the AFP head system. This separation allows the mandrel mass to be significantly reduced

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an intermediary support structure (the stationary mandrel) that provides the geometric framework for composite formation, while the actual composite application and rotation are performed by the AFP head system. This intermediary approach allows force reactions to be distributed to the factory floor through the stationary mandrel support rather than requiring the mandrel itself to be massive

Inventive Principle:

Principle #24Intermediary (Mediator)

3Productivity

If the mandrel is rotated at high speed, then layup rate increases, but the large dynamic mass limits the achievable rotation speed

Engineering Contradiction:

Improvelayup rateVSAvoidrotating mass

Core Design Contradiction:

ProductivityVSWeight of moving object

Solution Approach 1:

The patent inverts who rotates by keeping the mandrel stationary and rotating the AFP head instead. This allows high layup rates to be achieved through fast rotation of the lightweight AFP head rather than being limited by the rotation speed of a massive mandrel

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent transitions from a static mandrel to a dynamic AFP head system that can rotate rapidly. The AFP head is designed with low mass and high dynamic capability, allowing it to achieve the high rotation speeds needed for rapid layup while the stationary mandrel provides stable geometric support

Inventive Principle:

Principle #15Dynamics

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

This approach eliminates the need for massive mandrels, enhances layup speed, and increases production efficiency by using a stationary OML mold tool and a PKM manipulator, which applies high G-forces for better adhesion and reduced tool mass, thereby improving the efficiency and cost-effectiveness of composite material application.

Implementation Method 1

The high G-forces created by the PKM manipulator may serve to provide additional adhesion pressure to the composite materials as the speed of layup increases

Methodology Applied

Scientific EffectG-forces: Inertia

Data Source

PatentEP2436511B1Method and apparatus for laying up barrel-shaped composite structures

Publication Date: 2017.03.22 THE BOEING CO

AI summary

A body-of-revolution composite structure is fabricated by providing an OML mold (26) having an interior tool surface on which a composite layup may be formed and moving a manipulator (30) through the interior of the mold (26). An end-effector or AFP head (28) on the manipulator is used to apply composite material to the tool surface, and is moved circumferentially over the tool surface.