Document Type : Original Article

Authors

• Heshmatollah MohammadKhanlo ¹
• Ali Nouri ²
• Seyed Mohammad Kamali ¹

¹ Department of Shahid Sattari University

² Department of Shahid Sattri University

Abstract

Exposure to vibrations of certain frequencies can pose a risk to the pilot's body. During flight, the maneuvers performed by the pilot expose them to sudden and unfavorable accelerations, which can cause physical, physiological, and psychological problems. Research suggests that the use of seat suspension systems is effective in reducing high-frequency vibrations. However, for small movements, which occur at low frequencies between 2 to 15 Hz, the cushion of the pilot's seat plays a more significant role. In this research, we investigate the effect of the cushion on reducing vibrations on the pilot's body. Firstly, we compare and validate the results of the biodynamic equations of motion of a 4-degree-of-freedom model of the helicopter pilot's body with the experimental results. Next, we compare the biodynamic response of the motion in the finite element model (numerical solution) with the experimental results. Finally, we obtain and evaluate the biodynamic responses of the pilot's body movement by considering the cushion with different mechanical characteristics and in two stiffness and parallel (Kelvin-Voight model) and series (Maxwell model) damper modes. The Kelvin-Voight model was found to be more accurate than the COMSOL model.

Keywords

• Whole Body Vibrations
• Pilot Seat Suspension System
• Biodynamic
• Transmissibility
• Mechanical Impedance
• Apparent Mass

Main Subjects

• Aerospace Structures