Abstract The behaviour of multi-material systems subjected to dynamic loads is currently a topic of interest. This paper aims to study the performance of an impedance-graded multi-metallic (IGMM) system in mitigating the effects of stress waves generated during a high-velocity impact event. The IGMM system was designed by placing different metals in their reducing order of impedance. The experimental work was carried out using a single-stage light gas gun with a steel flyer fired at a velocity of 350 m/s. Armour-grade steel, titanium and aluminium were chosen as the materials and were used to design monolithic, bi-metallic and tri-metallic impedance graded targets. The free surface velocity of the final material in the target was measured using PDV probes and the generated velocity profile was used to quantify the Hugoniot Elastic Limit and the magnitude of the transmitted shock waves. A two-dimensional axisymmetric numerical model was used to simulate this impact event, which was carried out using the non-linear finite element code LS-DYNA. An analytical model was developed based on the shock wave propagation theories, using Matlab, to quantify the magnitude of the stresses within the different materials in the target. The output from the numerical and analytical models were in good agreement with the experimental results. The main findings from this study highlighted the potential of the IGMM system in reducing transmitted compressive stresses as well as prevention of spalling during impact loading events.

中文翻译：

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通过阻抗分级多金属系统的冲击波传播的实验、数值和分析研究

摘要 承受动态载荷的多材料系统的行为是当前的一个话题。本文旨在研究阻抗分级多金属 (IGMM) 系统在减轻高速撞击事件中产生的应力波影响方面的性能。IGMM 系统的设计是通过按阻抗的降序放置不同的金属。实验工作是使用带有钢制飞行器的单级轻气枪以 350 m/s 的速度发射的。选择装甲级钢、钛和铝作为材料，用于设计单片、双金属和三金属阻抗梯度靶。目标中最终材料的自由表面速度使用 PDV 探头测量，生成的速度分布用于量化 Hugoniot 弹性极限和传输的冲击波的幅度。二维轴对称数值模型用于模拟该撞击事件，该模型使用非线性有限元代码 LS-DYNA 进行。基于冲击波传播理论，使用 Matlab 开发了一个分析模型，以量化目标中不同材料内的应力大小。数值模型和解析模型的输出与实验结果非常吻合。这项研究的主要发现突出了 IGMM 系统在减少传递压缩应力以及防止冲击载荷事件期间剥落方面的潜力。