Project Title: Morphing Aircraft Wing

Team: Aeromorph 5

Team Members: Chad Glerum, Bill Grichin, Greg Haggarty, Joe Regel, Carrie White

Corporate Sponsor: NextGen Aeronautics

Corporate Contact: David Cowan

Faculty Coach: Dr. Mary Frecker

Date: Fall 2003

Project Overview

As part of its involvement in DARPA's Morphing Aircraft Structures (MAS) program, NextGen has identified several aircraft wing shape changes that have been shown to provide attractive military mission enhancements. The goal of this capstone design project will be to design a morphing aircraft wing to produce the TSChWing shape transformation. Using mechanisms and structures theories, the students will then design a structure that demonstrates the specified motion and is capable of carrying the critical wing air loads. The final deliverable item will be a working scaled prototype of the structure which can be proof-loaded by the application of mass to the model at appropriate hard points and actuated under load. The motion of the model should be smooth and continuous and require minimum power to effect.

Objectives

1.  Build solid model of design using ProEngineer or SolidWorks and perform FEA analysis using Matlab and/or ANSYS.  Ensure model deformation is within acceptable limits and that model will not fail under loading.

2.  Build prototype of morphing wing.  (Number of bays to be built dependent upon the complexity of the structure.)

3.  Design will conform to the following two wing geometries as closely as possible, dependent upon the morphing design used.  Unmorphed state consists of a 102 inch half span wing with a 20.4 inch chord, no sweep and Clark-Y airfoil.  The morphed state consists of a 47.6 inch half span wing with an 18.77 inch chord, 43 degree sweep and similar Clark-Y airfoil.

Final Design

Description:  Our final design consists of a repeating scissor linkage mechanism.  The links are attached to one another using pin joints as shown in the sketches below.  The following diagrams display a one-half span representation of the scissor linkage design.

     Unmorphed                                                             Morphed

         (Large Aspect Ratio)                                             (Small Aspect Ratio)

Design Benefits:  The following chart compares how different rib link lengths affects the wing's planform area and span.  Longer rib links result in a greater percent reduction in both planform area and span.

Taking into account the amount of space available in the wing for the scissor linkage structure, the optimum design chosen used a 12.5 inch rib link.  Based on this link, the following wing specifications were calculated.

Design Analysis Results:  A finite element analysis was performed on the design using ANSYS.  The analysis determined the cross sectional area of the links needed to support the the wing under flight loads.  Due to the small space available vertically in the wing, the links were designed with a larger width than height.  The final links were 2 inches wide by .75 inch high.  Using these parameters in the analysis resulted in a maximum deflection of approximately 1 inch at the tip of the wing and a maximum stress in the links attached to the fuselage of 32.6 ksi.  The following plots show the deflection of the wing under air loads and a contour plot of the element stresses in the structure. 

Design Prototype:  A working prototype of the wing structure was created to demonstrate how the wing will morph.  Below is a picture of the prototype in the unmorphed and morphed states.

Unmorphed                                                                               Morphed                          

(Large Aspect Ratio)                                                                 (Small Aspect Ratio)