TRIBHUVAN UNIVERSITY
Institute of Engineering, Pulchowk Campus
Department of Mechanical and Aerospace Engineering
Assignment Submission Cover Sheet
Assignment Title: Structural analysis of Wing
Student number: 078bas006
Course code:
Name: Amogh Adhikari
-
Course title: Finite Element Method
Email: 078bas006.amogh@pcampus.edu.np
Submission deadline: 02/06/025
Programme: Undergraduate in Aerospace Engineering
Mentor: Er. Abhimanyu Khadka
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Submission date :02/06/2025
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TRIBHUVAN UNIVERSITY
Institute of Engineering, Pulchowk Campus
Department of Mechanical and Aerospace Engineering
STRUCTURAL ANALYSIS OF RIGHT WING OF “BOSS”
Introduction
BOSS is an unmanned aerial vehicle (UAV) specifically designed for intelligence, surveillance
and reconnaissance (ISR) purpose. The UAV’s wing is made of NACA 2412 airfoil and there
is no twist, sweep or taper. The CAD model was designed in CATIA V5 R21. Structural
analysis of right wing of the aircraft was done in Ansys Structural. Pressure load was imported
from Fluid flow (CFX).
Methodology
1. CAD Modelling
Airfoil
Sweep, Taper, Twist
Chord Length
Wingspan
No. of Ribs
No. of circular spar of 50mm diameter
Material Used
NACA 2412
Absent
1,600 mm
10,000 mm
11
2
Ti-6Al-4V
Fig: Rib Design in CATIA
It is necessary to first collect the crucial airfoil coordinates to create the genuine solid
3D body of the rib in CATIA. The chord length and pitch angle inputs were used in the
airfoil plotter to generate the coordinates of NACA 2412 to obtain the data points for
the essential airfoil. After obtaining the airfoil coordinates, GSD Micro was used to
retrieve the data points for the airfoils in the CATIA part design, which, when projected,
revealed the airfoil curve.
Then cuts for structural components at the bottom were created, along with spar holes
at 25% of the chord for the entire span and spar holes at 50% of the chord for the main
body. Numerous cuts were made in the ribs to lessen the weight because it is always
necessary to lower the weight of structural components as much as possible when
constructing an aircraft for light weight criteria.
TRIBHUVAN UNIVERSITY
Institute of Engineering, Pulchowk Campus
Department of Mechanical and Aerospace Engineering
All the parts were assembled in assembly design and skin of the wing was generated
with surface design feature with 5mm thickness.
2. Ansys Workbench
Fig: Project Schematics in Ansys Workbench
For the analysis of Pressure load, Fluid Flow (CFX) system is used.
Fig: CFX analysis System
TRIBHUVAN UNIVERSITY
Institute of Engineering, Pulchowk Campus
Department of Mechanical and Aerospace Engineering
TRIBHUVAN UNIVERSITY
Institute of Engineering, Pulchowk Campus
Department of Mechanical and Aerospace Engineering
Static Structural
a. Mesh
Number of total nodes = 434161
Number of contact elements = 33091
Number of spring elements = 0
Number of bearing elements = 0
Number of solid elements = 238845
Number of condensed parts = 0
Number of total elements = 271936
Fig: Mesh Generation over the geometry
Element Order
Element Size
Curvature min Size
Curvature Normal Angle
Element Quality
Aspect Ratio
Skewness
Quadratic
3.28 e-002
3.28 e-004
30 Degrees
0.866
1.75
0.21
TRIBHUVAN UNIVERSITY
Institute of Engineering, Pulchowk Campus
Department of Mechanical and Aerospace Engineering
b. Applied Load
Fig: Loading on the Surface of wing
Fig: Imported Pressure From CFX
Fig: Total Static Deformation
TRIBHUVAN UNIVERSITY
Institute of Engineering, Pulchowk Campus
Department of Mechanical and Aerospace Engineering
Fig: Total Equivalent Stress
Fig: Modal Frequency
Fig: Modal Shapes
TRIBHUVAN UNIVERSITY
Institute of Engineering, Pulchowk Campus
Department of Mechanical and Aerospace Engineering
Fig: Harmonic Response Under the same Loading Condition.
Discussion
•
Resonance: The peak at 7.7 Hz is the indicative of a resonance in the system being
analyzed. This means that at this frequency, the system is most responsive, possibly
due to natural frequencies aligning.
•
System Damping: The gradual decline posts the resonant frequency suggests that the
system is damped, meaning the response reduces over time or with higher
frequencies.
TRIBHUVAN UNIVERSITY
Institute of Engineering, Pulchowk Campus
Department of Mechanical and Aerospace Engineering
•
Application: To prevent wing fluttering at that frequency, spar cross section and
material needs to be modified.
Besides this, our result might have been affected by the poor definition wing loading
and operational regime. During our CFX analysis, the mesh quality was also
somewhat poor to reduce computational time, and it could be refined for better
accuracy. The boundary conditions could be defined better for accurate pressure
reading. Due to absence of information about fuel storage location in wing structure,
an estimation was made which might have lead difference in analysis from actual
response.
Result and Conclusion
We were able to perform structural analysis on the UAV’s wing. From our analysis, the
design and material selection were up to the standard. The spar cross section may need to
improve depending on the necessity of the modal frequency damping.
Reference
BOSS - A SURVEILLANCE UAV (APD poster presentation)
Authors: Bhawana Pokharel, Osika Shakya, Shreyas Shrestha, Swikriti Puri