Numerical analysis of the structural response of armoured vehicles subject to ballistic impacts

摘要

Ballistic impacts on armoured vehicles cause shock effects that are transmitted in the structure to the occupants and equipment. These often exceed the human and systems limits. For a design engineer, reducing the shock levels transmitted to the occupant and to the onboard equipment requires the use of specific analysis tools and methods. A complete numerical methodology has been developed by ONERA-Lille to treat this problem, the main objective of which is to be easily usable by industrials to improve their structural design. A commercial finite element code is used, using explicit resolution methods. For computing cost reasons, the problem must be solved in several steps. In a first step, local impact on a real 3D armour geometry is simulated. The complete description of the shock transmission is extracted from this simulation by an appropriated technique, in the periphery of the armour. Then, the evolution of these data is described through load functions, introduced as new inputs in the model of the complete structure. The natural response of the structure can then be analysed, in terms of stress waves on the one hand, and of shock spectrums measured at the equipment's position on the other hand.