Department of Mechanical & Aerospace Engineering
Department of Mechanical & Aerospace Engineering
Department of Mechanical & Aerospace Engineering
Department of Mechanical & Aerospace Engineering
Topic Area
Aerospace Engineering
Mechanical Engineering
Planar Trusses
Engineering Statics
Engineering Statics
Planar Mechanisms
Engineering Dynamics
Engineering Dynamics
Planar Frames
Solid Mechanics
Solid Mechanics
Planar Heat Conduction
Planar Mass-SpringDamper Systems
Heat Transfer
Vibrations
Vibrations
Topic Area
Computer Science
Variety
Introduction to MATLAB
Department of Mechanical & Aerospace Engineering
MATLAB GUI
Software Development
GUI Design & Assessment
MATLAB
Backend
Code
Will Morrow,
Comp. Sci MS Candidate
Sean Maguire,
Konner White,
ME, MS Candidate BS in ME, AE
• Weekly Meetings Students & Faculty
• Testing with Undergraduate/Graduate Volunteers
Department of Mechanical & Aerospace Engineering
u=D–L
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k
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i
PkA
VkA
MkA
Pk (X)
Vk (X)
Mk (X)
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Department of Mechanical & Aerospace Engineering
Main Window
Main Window runs simulations
and displays or exports results.
Invokes the Editor Window.
Editor Window
Editor Window creates, edits, opens,
and saves designs
Department of Mechanical & Aerospace Engineering
Department of Mechanical & Aerospace Engineering
MATLAB Installed (2012b or higher)
 URL:

http://www.mae.ncsu.edu/academics/mae-course-websites.php
At the bottom of the webpage click: Matlab App
Double click on the file CADApp_Truss.mlappinstall
Department of Mechanical & Aerospace Engineering
Note: yE=16.32 mm (nonlinear)
Department of Mechanical & Aerospace Engineering
Return to Editor
Move a Node
•
Using the Mouse
•
Using Nodal Properties Table
Change the Length of a Member
•
Using the Mouse
Node Deletion
•
Using the Mouse Middle Button
Importing and Exporting Schematic Files
•
Using the Import from File Button and
the Export to File Button
Department of Mechanical & Aerospace Engineering
Eiffel said in 1887 (Le Temps (Paris), February 14):
“Now to what phenomenon did I give primary concern in
designing the Tower? It was wind resistance. Well then! I
hold that the curvature of the monument's four outer edges,
which is as mathematical calculation dictated it should be
… will give a great impression of strength and beauty, for it
will reveal to the eyes of the observer the boldness of the
design as a whole.”
As proof of the tower's effectiveness in wind resistance, it sways
only 6–7 cm (2–3 in) in the wind.
____________
Named after the engineer Gustave Eiffel, whose company designed and built
the tower.
Erected in 1889 as the entrance arch to the 1889 World’s Fair
The tallest building in Paris; most-visited paid monument in the world; 6.98 million
people ascended it in 2011. The tower received its 250 millionth visitor in 2010.
324 meters (1,063 ft) tall, about the same height as an 81-story building.
Has 3 levels for visitors, with restaurants on the 1st and 2nd. From ground level to
the 1st level is over 300 steps, same from the 1st to the 2nd. There are stairs to the
3rd level but these are usually closed to the public and it is generally only
accessible by lift.
Department of Mechanical & Aerospace Engineering
Top platform
2nd platform
1st platform
Challenge:
Find the widths of the 1st and 2nd platforms subject to the
constraint that the total width L1+L2= 339ft in order to
minimize the lateral deflection at the top platform
Hint:
Begin the iterative design process with the
baseline configuration in file JWEEiffel.schm.
Department of Mechanical & Aerospace Engineering
Top PLatform Deflection, d, ft
Eiffel Tower Stiffness Optimization
0.3
0.2
0.1
150
160
170
180
190
200
210
220
230
1st Platform Width, L1, ft
Minimum deflection is 0.207 ft = 2.5 in at the top
when L1 ≈ 200 ft and L2 ≈139 ft.
Actual Eiffel tower dimensions are
L1 = 216 ft and L2 = 123 ft.
Given the simplicity of our 2D truss model, the
insight than can be achieved is remarkable
240