典型机身结构撞击不同环境目标损伤特性数值研究

NUMERICAL STUDY ON IMPACT CHARACTERISTICS OF TYPICAL FUSELAGE STRUCTURES AGAINST VARIOUS ENVIRONMENTAL TARGETS

  • 摘要: 机身结构在撞击事件中的响应因其突发性和破坏性而成为航空安全领域关注的焦点。本文采用ALE方法,对典型机身结构在不同速度下撞击不同环境目标(刚性地面、软土和水)时的损伤特性进行了分析,得到了机身结构在不同撞击条件下的应力、应变及加速度等动态响应,探讨了撞击速度与环境目标的物理特性如何共同影响机身结构的损伤模式。研究发现,机体结构的加速度演变趋势整体上与受力特性具有高度的一致性,但不同部件的加速度响应却各有差异;蒙皮、桁条和隔框作为主要的能量吸收部件,在不同撞击条件下展现各异的吸能特性,并形成三种基本损伤模式:在撞击刚性地面时,机身底部被压平,隔框形成两点塑性铰(损伤模式Ⅰ);在撞击软土时,底部机身结构发生塑性铰和内凹(损伤模式Ⅰ和Ⅱ的结合);而在撞击水面时,机身蒙皮和桁条结构向内凹陷(损伤模式Ⅲ)。

     

    Abstract: The response of an aircraft fuselage structure during impact events has become a focal point of concern in the field of aviation safety due to its sudden and destructive nature. This study employs the Arbitrary Lagrangian-Eulerian (ALE) method to analyze the damage characteristics of a typical fuselage structure when it impacts different environmental targets (rigid ground, soft soil, and water) at various velocities. The dynamic responses such as stress, strain, and acceleration of the fuselage structure under different impact conditions were obtained, and the study explored how the impact velocity and the physical properties of the environmental targets jointly affect the damage patterns of the fuselage structure. The research found that the overall trend of the acceleration evolution of a fuselage structure is highly consistent with the characteristics of the force it experiences, but the acceleration response of different components varies. The skin, stringers, and frames, as the main energy-absorbing components, exhibit different energy absorption characteristics under various impact conditions and form three basic damage patterns: when impacting the rigid ground, the bottom of the fuselage is flattened, and the frames form two plastic hinges (Damage Pattern I); when impacting soft soil, the bottom structure of the fuselage undergoes plastic hinges and dents (a combination of Damage Patterns I and II); and when impacting the water surface, the fuselage skin and stringer structures indent inward (Damage Pattern III).

     

/

返回文章
返回