Shape Memory Alloy Actuator for Morphing Wing Flap Curvature

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Solution Overview

Problem

Conventional wing-flap systems are heavy, complex, and limited in aerodynamic curvature modification, leading to increased weight, operating, and maintenance costs, as well as suboptimal lift performance during take-off and landing.

Innovation Solution

A morphing wing-flap assembly utilizing shape memory alloy actuator devices that dynamically modify the wing's curvature, reducing weight and complexity by using a combination of shape memory alloy elements and elastic arch frameworks for controlled deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional control lines and actuation devices are used for wing-flap deflection, then the flap can be deflected to specific angles, but the weight of the wing structure significantly increases

Engineering Contradiction:
Improveflap deflection controlVSAvoidwing structure weight
Core Design Contradiction:
Ease of operationVSWeight of moving object

Solution Approach 1:

The patent extracts and eliminates the heavy conventional control lines and complex actuation devices from the wing structure. Instead, it uses shape memory alloy elements that can be directly integrated into the flap structure, removing the need for separate robust control mechanisms and significantly reducing overall weight.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the conventional mechanical actuation system (control lines, motors, linkages) with a smart material-based system using shape memory alloys. These alloys undergo phase transformation to produce actuation forces directly, eliminating the need for complex mechanical transmission components and reducing weight.

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

2Device complexity

If conventional flaps with fixed deflection angles are used, then the structure is simple, but the aerodynamic curvature modification is limited

Engineering Contradiction:
Improveflap structure complexityVSAvoidcurvature modification capability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent transforms the static, fixed-angle flap structure into a dynamic, continuously adjustable curvature system. The shape memory alloy elements can be activated to different degrees, allowing the flap to assume multiple curvature states beyond discrete deflection angles, thereby enhancing adaptability while maintaining structural simplicity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the physical state and properties of the shape memory alloy elements through thermal or electrical activation, enabling continuous variation of the flap curvature. This allows the same simple structure to achieve multiple aerodynamic configurations by changing the activation parameters of the smart material.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If robust control lines and complex actuation devices are used, then reliable flap deflection is achieved, but operating and maintenance costs increase

Engineering Contradiction:
Improveflap deflection reliabilityVSAvoidmaintenance cost
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The shape memory alloy elements are inherently reliable with no moving parts, control lines, or mechanical linkages that can wear or fail. The system is self-contained, with the smart material directly producing actuation forces, eliminating the need for maintenance of complex mechanical components and reducing operating costs.

Inventive Principle:
Principle #25Self-service

4Ease of operation

If conventional actuation systems are used, then the flap can be controlled, but the system weight and complexity significantly increase

Engineering Contradiction:
Improveflap control capabilityVSAvoidactuation system complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent merges the actuation function directly into the flap structure using shape memory alloy elements that are integrated with the flap anatomy. This eliminates separate actuation systems and control lines, combining structural and actuation functions into a single unified system that is both simple and effective.

Inventive Principle:
Principle #5Merging (Combining)

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 significantly reduces weight and operational costs while enhancing aerodynamic performance by allowing dynamic curvature adjustment with low energy consumption and multiple stable states, mimicking conventional flap deflections.

Implementation Method 1

an extended element (11) made of shape memory alloy

Methodology Applied
Scientific EffectShape memory alloy phase transformation: Shape Memory Alloy

Implementation Method 2

A controlled heating of the extended element (11), sufficient to trigger a transformation of the crystalline phase of the shape memory alloy, is capable of causing a contraction of the extended element (11)

Methodology Applied
Scientific EffectThermal expansion/contraction: Thermal Expansion

Implementation Method 3

an arch-shaped framework (12) made of elastic material, in particular a metallic one. Such an arch-shaped framework (12) has thicknesses and is geometrically shaped so as to be able to linearly deform due to the stress exerted by the extended element (11)

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP2147856B1An actuator device based on a shape memory alloy, and a wing flap assembly fitted with such an actuator device
Publication Date: 2011.10.12 ALENIA AERMACCHI
  • EP2147856B1 patent drawingFigure 1~2
  • EP2147856B1 patent drawingFigure 3a~5b
  • EP2147856B1 patent drawingFigure 6~7

AI summary

A wing-flap assembly comprises a flap (20; 200) made up of a plurality of flap sections (21, 22, 23; 201, 202, 203, 204), in which each flap section is connected to the preceding one in a rotatable manner, and one or more actuator devices (10) adapted to control the rotation of the flap sections. Each actuator device comprises an extended element (11) made of shape memory alloy and an arch-shaped framework (12) made of elastic material, to which the extended element is fixedly connected under tension. Each end (11a, 11b) of the extended element is fixed to a respective end (12a, 12b, 12ab) of the arch-shaped framework. At least one of the actuator devices is connected at one end to the first of the flap sections, and on the other side it is adapted to be connected to a wing structure (W).