Impact Loads on the Occupant under the Protection of an Inversion Tube Energy Absorber during a Helicopter Crash

Yunhua Luo,Tao Yan,Lingjie Wang,Mengqi Wang,J Detand,D Ruxu

doi:10.1051/matecconf/201816703009

Abstract

The objective of this paper is to investigate the impact loads on the occupants’ head, neck, and spine under the protection of an inversion tube energy absorber during a helicopter crash landing. Due to the high vertical acceleration, the head, neck and spine are the most vulnerable parts of a body, so that an energy absorber is needed to dissipate the kinetic energy of the occupant and the seat to minimize the impact loads. In this paper, an inversion tube was adopted as an energy-absorbing device. The occupant injury conditions were evaluated by a numerical simulation. The result indicates that the impact loads on occupant’s head, neck and spine are below the regulated thresholds under the protection of the energy absorber when the helicopter crash at a speed of 12.81m/s in vertical direction. As a consequence, the design of the occupant protection system has been proven reliable.

Highlights

Occupant protection is one of the most basic requirements for the helicopter seat structure design
To evaluate the reliability of the impact-alleviation system design, the occupant injure severity was investigated by a numerical simulation
It can be concluded that the inversion tube design is reliable, for that the HIC value, impact loads on the neck and the spine and belt force are all under the regulated thresholds under the protection of the shock-mitigation system

Summary

Introduction

Occupant protection is one of the most basic requirements for the helicopter seat structure design. To attenuate the impact loads on the occupant, the seat must process enough energy-absorbing capacity to dissipate the kinetic energy of the occupant and the seat before it bottoms out. Michle Guida et al [2] proposed an innovative method of integrating anticrash energy absorbers made of a new composite material into landing gears to absorb the kinetic energy of the seat and the subfloor of a helicopter. S.A. Galehdari et al [1] developed a graded honeycomb shock absorber to attenuate the impact loads on the occupant to an acceptable level. Zhang [3] designed a sliding seat for preventing the neck from severe injury. The inversion tube is one of the most commonly used energy absorber for its excellent performance in absorbing energy, high manufacturability and low cost [4]

Objectives

Results

Conclusion