Static Load Analysis of Various Wing Spar Profiles: A Comparative Study between Mathematical and Finite Element Methods

Widyawasta Widyawasta, Alief Wikarta


Unmanned aerial vehicles (UAVs) have become increasingly essential in both civilian and military contexts, serving various roles such as surveillance, mapping, cargo transport, and specialized tasks. The demand for long-endurance surveillance UAVs is critical for covering vast areas continuously, prompting the development of Medium Altitude Long Endurance (MALE UAV). This paper explores the structural strength analysis of various wing spar profiles of MALE UAV using mathematical analysis and Finite Element Method (FEM) under static loads. The wings, pivotal for generating lift, are subjected to rigorous operational loads, necessitating robust structural reliability. While mathematical analysis provides fundamental insights, FEM allows for detailed simulations under various conditions. Comparative studies between mathematical analysis and FEM are conducted to validate the structural strength of MALE UAV wings, with a focus on different spar profiles. Aluminum Al7075-T6 is used as the material, with convergence tests ensuring FEM accuracy. The comparative analysis highlights significant variations in normal and shear stress among different spar profiles, with the widest disparities observed at the wing root, 6.40 and 1 MPa resp., and the least, 1.51 and 0.63 MPa, close to the wing tip position at 6.75 m. These insights underscore the critical role of structural integrity in optimizing UAV performance and reliability.


structural strength; FEM; spar profiles; mathematical analysis

Full Text:



S. Ali, O. Hassan, A. Gopalakrishnan, A. Muriyan, and S. Francis, “Unmanned Aerial Vehicles: A Literature Review,” Journal of Hunan University Natural Sciences, vol. 49, no. 7, pp. 96–113, Jul. 2022, doi: 10.55463/issn.1674-2974.49.7.11.

A. A. Laghari, A. K. Jumani, R. A. Laghari, and H. Nawaz, “Unmanned aerial vehicles: A review,” Cognitive Robotics, vol. 3, pp. 8–22, 2023, doi: 10.1016/j.cogr.2022.12.004.

F. Hasim, A. F. Widodo, and Sariman, “Analisa Prestasi Terbang Dan Kestabilan Pesawat Udara Nir-Awak (PUNA-BPPT) Prototipe Sriti Menggunakan CFD,” in SIPTEKGAN XVI-2012, pp. 341–351. [Online]. Available:

F. R. Triputra, B. R. Trilaksono, R. A. Sasongko, and M. Dahsyat, “Longitudinal dynamic system modeling of a fixed-wing UAV towards autonomous flight control system development: A case study of BPPT wulung UAV platform,” in 2012 International Conference on System Engineering and Technology (ICSET), Bandung, West Java, Indonesia: IEEE, Sep. 2012, pp. 1–6. doi: 10.1109/ICSEngT.2012.6339294.

M. K. Sawant and D. A. G. Dahake, “A New Hyperbolic Shear Deformation Theory for Analysis of Thick Beam,” vol. 3, no. 2, 2007.

O. A. Dada, O. M. Makinde, O. C. Ubadike, and P. O. Jemitola, “A Taguchi based iterative wing structural design for a low speed, hybrid UAV,” Nig. J. Tech., vol. 41, no. 1, May 2022, doi: 10.4314/njt.v41i1.12.

G. Visnjic, D. Nožak, F. Kosel, and T. Kosel, “Reducing shear-lag in thin-walled composite I-beam wing spars,” Aircraft Eng & Aerospace Tech, vol. 86, no. 2, pp. 89–98, Feb. 2014, doi: 10.1108/AEAT-09-2012-0153.

M. L. Cassão Gatelli, L. Gomes, C. E. De Souza, and D. Milbrath De Leon, “A MDO PROCESS FOR PRELIMINARY DESIGN OF A REMOTELY PILOTED AIRCRAFT,” in Anais do X Congresso Nacional de Engenharia Mecânica, ABCM, 2018. doi: 10.26678/ABCM.CONEM2018.CON18-0771.

B. N. Bharath Chinni and P. N. Siddappa, “Design and analysis of front spar wing-tip segment for a small transport aircraft,” Materials Today: Proceedings, vol. 52, pp. 1846–1851, 2022, doi: 10.1016/j.matpr.2021.11.494.

O. Schrenk, “A simple approximation method for obtaining the spanwise lift distribution,” NTRS NASA, NACA-TM-948, Aug. 1940. [Online]. Available:

J. Fuentes, S. Cicero, F. Berto, A. Torabi, V. Madrazo, and P. Azizi, “Estimation of Fracture Loads in AL7075-T651 Notched Specimens Using the Equivalent Material Concept Combined with the Strain Energy Density Criterion and with the Theory of Critical Distances,” Metals, vol. 8, no. 2, p. 87, Jan. 2018, doi: 10.3390/met8020087.

ASM Handbook Committee, ASM Handbook Volume 2: Properties and Selection: Nonferrous Alloys and Special-Purpose Materials, vol. 2. 1990. [Online]. Available:


Creative Commons License
JMES The International Journal of Mechanical Engineering and Sciences by Lembaga Penelitian dan Pengabdian kepada Masyarakat (LPPM) ITS is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
Based on a work at