VIBRATION RESPONSE ANALYSIS ON A UAV WITH A HIGH ASPECT RATIO WING TO TURBULENT LOAD AT LOW ALTITUDE (HALE ITB V4 CASE STUDY)

• Main Author: Gusto Andika, Matza
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/76332
• Institution: Institut Teknologi Bandung

As a high altitude platform with a high aspect ratio, the HALE unmanned aircraft is prone to structural failure when flying at low altitudes due to turbulence load, as was the case with the Helios HP-03 aircraft. ITB also anticipated the turbulence load problem in the development of the HALE aircraft by conducting comprehensive studies on the phenomenon of structural response to turbulent loads. Due to its complex geometry (twin wing and triple boom), the HALE ITB will generate a highly complex structural dynamic response when interacting with turbulent loads. It can be challenging to produce aeroelastic solutions that are efficient in terms of testing time and precision. The focus of the research is the integration of numerical and experimental analysis. The structure's numerical model was developed using the design data of the HALE ITB structural configuration. In addition, a structural vibration test was conducted to validate and update the constructed numerical model. In this study, a procedure for integrating numerical and experimental methods is proposed, in which the determination of excitation points and response measurements are performed by incorporating the results of the initial numerical analysis using the kinetic energy approach in the structural vibration test procedure. By requiring fewer measurement sites, this method makes the vibration testing procedure more efficient. The Doublet Lattice method and finite elements are used to model fluid and structure interactions, while the Von Karman model is used to model turbulence disturbances. The updated numerical results of the dynamic characteristics of the structure derived from vibration test results are tested by the turbulent load. The results demonstrated that HALE ITB V4 were harmful in instances of high turbulence intensity (severe). This is due to the significant amplitude of the structure's vibration in the wing tip, which is 30% of the wing's half span at a flight speed of 12 m/s. The vibrations have a lower frequency (0.198 Hz) than the natural frequency of HALE flexible structure (1.15 Hz). The kinetic energy approach used in the vibration test design generates 10 measurement points, which is more efficient than the previous test, which used 160 points with a smaller wing aspect ratio.