MECH2300 Structures and Materials

Integrated Assignment 2023
The Wright Flyer "Kitty Hawk" was an iconic aircraft and its first sustained powered flight, on the 17th of December 1903, is one of the most historically significant events in the history of aviation. The 1903 Wright Flyer was a canard biplane configuration, with large elevators in front of the wings, twin pusher style propellers, and two rudders at the rear.
location of sparstrut chord
Figure 1. Kitty Hawk biplane (photo most likely taken by Orville Wright, USA Library of Congress); First Flight of December 17, 1903 (NASA Multimedia Library). [1]
The aircraft was made predominantly of wood and canvas. The Wright brothers spent years fine tuning the flyer design, including testing various wood samples to find the optimal spar material, wind tunnel testing to determine the most efficient wing strut cross section, and wing lift and drag calculations using a homemade bicycle wheel test rig. Appendix A shows a detailed image of the 1903 Kitty Hawk Wright Flyer.1
1 Use Appendix A, the references listed in this document and additional resources you have found to familiarise yourself with the terms used in this document, general aeronautical foundations and further details of Kitty Hawk.

Task 1 - Kitty Hawk Structural Analysis
You are tasked to conduct a static structural analysis to evaluate loads, stresses and deformations in the wing spars and wing-tip connecting strut.

• Use the following additional information to determine input parameters for your calculations:
• Use air density at standard sea-level atmosphere.

Both spars and struts are made from Sitka Spruce. Sitka Spruce is light but is exceptionally strong for its weight with excellent impact resistance (See Appendix C for Sitka Spruce property data). It is assumed that the spruce is loaded parallel to the grain. The spars have a constant rectangular cross section along the entire length, with the height equal to three times the width as shown in Figure 3a.
The vertical struts have cross-sectional dimensions as shown in Figure 3b.
3
Spar Cross-Section
10.3 [mm] r
54.0 [mm]
Flight
Direction
25.4 [mm]
Strut Cross-Section
Figure 3. a) Spar cross-section; b) Strut cross-section.
The results of your Task 1 analysis must include:

• Magnitudes of loads and critical stresses in the spars and struts.
• Safety factors for possible failure modes of those structural elements.
• Critical discussion of additional design aspects.

Task 2 - Performance of Different Materials
How would have the Wright brothers' Kitty Hawk design perform if they had access to modern materials? In Task 2 you will explore the use of five modern materials including two different Al alloys, stainless steel, a glass-fibre composite and a carbon-fibre composite.
All aircraft and flight parameters are kept the same as in Task 1 including the shape and width to height ratios of the spar and strut cross-sections. The only parameter that is changing is the total mass of the spars which was defined as 100 kg in Task 1.
In your materials selection analysis you need to compare the performance of the original Sitka Spruce Kitty Hawk with spars and struts manufactured from the different materials listed above. To support this quantitative assessment, include some typical safety factors for the various failure modes (such as plastic failure or buckling).
This task should include both quantitative analysis which is then extended by a qualitative critical discussion to reach the final material of choice for the wing spars and struts.
To extend the materials selection analysis, discuss other aircraft and aeronautical aspects which explain why some materials are the preferred choice used in aircraft wings. This could include discussion around fracture toughness, fatigue properties, cost or joinability/manufacturability.

Report
A concise but full report is required. It should not exceed 2000 words. The report should start with an Executive Summary which a busy manager could read and obtain all of the information they need on which to act. The body of the report should summarise your analysis, assumptions made, and a critical analysis of your findings. The report should finish with a brief conclusion that recaps the major results and recommendations. Detailed working should be included as an appendix and should have enough detail for a reader to follow what you have done. The appendix is not included in the above word limit.
The report can be prepared individually or in pairs. The coversheet of the report has to include all details of the student(s), who have created it (First name, Family name, Student ID). The report is due on Thursday, 25th of May 2023 at 1 pm. It is submitted through the Turnitin link on Blackboard.