Advanced concepts for trailing edge morphing wings - Design and manufacturing of test rig and test samples - Test execution

Final Report Summary - SMYTE (Advanced concepts for trailing edge morphing wings - Design and manufacturing of test rig and test samples - Test

Executive Summary:

SMyTE proposes a technological research program allowing to develop, manufacture and validate actuators by integrating a number of various emerging SMA technologies that result in high performance/ high reliability actuators. The innovative aspects of the proposed technologies are new SMA material concept with high power-to-weight ratio and high performance & reliability optimized for later application into a morphing/adaptive wing. Thanks to these new technologies, the SMyTE actuator system could contribute to lower mass (compared to a conventional mechanical/hydraulic actuator), be fully integrated (at a later stage) within a regional aircraft.

The purpose of SMyTE is technology based on high performance material and optimized architecture and it is multifold. When applied to perform camber variations of a movable flap, it increases airfoil performance with respect to specific requirements which will lead to following benefits i.e.: at first, SMyTE can significantly improve TE aerodynamics offering a greater operational envelope compared to a conventional TE flap device. Secondly, by eliminating conventional flap actuation mechanisms it can provide weight benefits and thus reduction of fuel consumption. As third, being utilized as a flight control surface replacement, it locally improves the aerodynamics in the TE vicinity during flight further adding to drag and fuel reduction.

Project Context and Objectives:

Key objectives

• Design and mechanical analysis of the so called Deeply Embedded Shape Memory Actuator (DESA) architecture mechanism. Based on the inputs from T1.1 and the data for the SMA actuators provided by the Topic Manager the DESA architecture will be designed and analysed by in-house developed FEA modules that allow for accurate simulation of the shape memory effects. The output of this task will be 3D CAD models and design drawings that will be used for DESA manufacturing.
• Design analysis and manufacturing if the test rig and the interface for DESA and Smart Actuated Compliant Mechanism (SACM) architectures. The design of the test rig will be supported by FEA analysis in order to assure that proper safety margins for static and dynamic loading exist and that the dynamic characteristics of the test rig will not influence the dynamic response of the trailing edge concepts that will be eventually assessed. The outcome of this task will be 3D CAD models and manufacturing drawings of the test rig.
• Manufacturing of the DESA prototype. Functionality tests will be carried out in order to fine tune the different components (SMA actuators and bias elements-springs) and proof the concept.
• Experimental characterisation of DESA and SACM architectures

Project Results:

The work performed in the current project period followed consequently the set objectives.

WP1: Definition and Specifications

In WP1, the work provided useful inputs to the rest of work packages. More specifically the various project requirements are covered within the following tasks:

• T1.1 DESA Specifications
• T1.2 SACM Specifications
• T1.3 Test rig specifications
• T1.4 Test Plan Specifications

WP-2: Design and Analysis of DESA architecture

WP 2 concerns the design and mechanical analysis of the DESA architecture mechanism. Based on the inputs from T1.1 and the data for the SMA actuators provided by the Topic Manager the DESA architecture was designed and analysed by in-house developed FEA modules that allow for accurate simulation of the shape memory effects. With the aid of these modules the static and dynamic behaviour of the DESA architecture will be modelled and critical design parameters will be evaluated. The output of this task was the 3D CAD models and design drawings that will be used for DESA manufacturing.

WP-3: Testing Rig and Interface Manufacturing

The third work package deals with design analysis and manufacturing if the test rig and the interface for DESA and SACM architectures. The design of the test rig was supported by FEA analysis in order to assure that proper safety margins for static and dynamic loading exist and that the dynamic characteristics of the test rig will not influence the dynamic response of the trailing edge concepts that will be eventually assessed. The outcome of task T3.1 was the 3D CAD models of the test rig and manufacturing drawings of the test rig. With the manufacturing drawings from T3.1 a metallic frame-like construction has been manufactured that is able to host DESA and SACM architectures. This will allow the testing under several operative, defined in the test plan.

WP-4: DESA Manufacturing and Functionality Tests

Based on the manufacturing drawings of WP-2 the prototype has been manufactured. Functionality tests were carried out in order to fine tune the different components (SMA actuators and bias elements-springs) and proof the concept. Within WP4 and more specifically in T4.1 mechanical characterisation of the SMA actuators (in the form of SMA wires) has been performed as well as proper thermo-mechanical “training”. Both these activities have been proven necessary because the material data from SMA manufacturers tend to be unreliable with considerable batch to batch variations. Works in WP4 have been completed.

WP-5: Experimental Characterisation of DESA and SACM

WP 5 deals with the experimental characterisation of DESA and SACM architectures. This will be done with the aid of the test rig that is manufactured in WP-4. The response of the two architectures under investigation will be assessed under static loads and dynamic excitation. At the end of P1 characterisation tests have been finished. Works will be ongoing for the improvement of DESA actuators.

Commercially available SMA has been used and an initial basic characterization phase was completed. The mechanical response of the actuator has been measured as function of temperature and load application. The aim is to have the material behaviour under static and dynamic conditions up to failure. The SMA wires have been trained in one-way actuation and will contract upon current application. The required force to bring the specimen back to initial position is provided by the internal stresses of the deformed structure that will “spring back” to its original shape after current is stopped. For the initial trials and to proof the concept, an intermediate transformation temperature SMA has been used (~65ºC).

Special care is given in the work focused on improving the SMA actuation cycle. For this purpose, the SMA wire actuators were tested on a special experimental set up that allows different cooling rates of the wires. The result was 50% shorter actuation cycles.

Potential Impact:

Impact

The use of electrically powered actuators integrating speed and position sensors is expected to enable to save weight, and to increase engine monitoring and diagnostics. Moreover, SMyTE project will allow to reduce the size of components of generation equipment as well as to achieve significant reduction in maintenance. Another aspect of SMyTE developments is increased reliability safety having great importance in aeronautic transport.

The following Dissemination Table present the dissemination activities performed during Periods 1 and 2 of the project.

Planned/ actual dates Type of audience Countries addressed Size of audience Partner responsible / involved

6/11/2012 Presentation of project at the AIRTEC conference in Frankfurt/Germany International 20 30 ARES

15/01/2013 Presentation of project in University of Patras Mechanical Engineering Dept. National 1 30 INASCO