Purpose

This paper aims to investigate the rebound process and the secondary-impact process of the fuselage section that occurs in the actual crash events.

Design/methodology/approach

A full-scale three-dimensional finite element model of the fuselage section was developed to carry out the dynamic simulations. The rebound process was simulated by removing the impact surface at a certain point, while the secondary-impact process was simulated by striking the impact surface against the fuselage bottom after the first impact.

Findings

For the rebound process, the fuselage structure restores deformation due to the springback of the fuselage bottom, and it results in structural vibration of the fuselage section. For the secondary-impact process, the fuselage deformation is similar with that of the single impact process, indicating that the intermittent impact loading has little influence on the overall deformation of the fuselage section. The strut failure is the determining factor to the acceleration responses for both the rebound process and the secondary-impact process.

Practical implications

The rebound process and the secondary-impact process, which is difficult to study by experiments, was investigated by finite element simulations. The structure deformations and acceleration responses were obtained, and they can provide guidance for the crashworthy design of fuselage structures.

Originality/value

This research first investigated the rebound process and the secondary-impact process of the fuselage section. The absence of the ground load and the secondary-impact was simulated by controlling the impact surface, which is a new simulating method and has not been used in the previous research.

中文翻译：

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回弹过程和二次撞击过程中机身断面的碰撞模拟

目的

本文旨在研究在实际坠机事件中发生的机身截面的回弹过程和二次撞击过程。

设计/方法/方法

开发了机身截面的全尺寸三维有限元模型来进行动态仿真。反弹过程是通过在特定点移除撞击面来模拟的，而二次撞击过程是通过在第一次撞击后将撞击面撞击到机身底部来模拟的。

发现

对于回弹过程，由于机身底部的回弹，机身结构恢复了变形，并导致机身部分的结构振动。对于二次冲击过程，机身变形与单次冲击过程相似，这表明间歇冲击载荷对机身部分的整体变形影响很小。支撑杆失效是反弹过程和二次冲击过程中加速度响应的决定因素。

实际影响

通过有限元模拟研究了难以通过实验研究的回弹过程和二次冲击过程。获得了结构变形和加速度响应，它们可为机身结构的防撞设计提供指导。

创意/价值

本研究首先研究了机身截面的回弹过程和二次撞击过程。通过控制冲击面来模拟地面载荷和二次冲击的不存在，这是一种新的模拟方法，在以前的研究中并未使用。