This study experimentally and numerically investigated the blast resistance of sandwich panels composed of steel face sheets and 3D-printed gradient auxetic chiral core. Five gradient strategies were utilized in the design of auxetic core, including uniform gradient, positive gradient, negative gradient, center positive gradient and center negative gradient. Varying blast loadings were applied by adjusting the masses of explosive charges. The deformation/failure modes of sandwich panels were obtained in the experiments, in terms of the face sheets and gradient auxetic core. The effects of impulse and gradient type of auxetic core on dynamic responses of specimens were examined. In addition, the numerical simulation was employed to clarify the deformation process of sandwich panel, and to analyze the deformation mode of auxetic cores under sufficient compression. It was shown that higher impulse was associated with increased plastic deformation in the face sheet and more serious shear and tensile tearing within the auxetic core. The auxetic cores of varying gradient types displayed distinct compress deformation behaviors. Among them, the negative gradient variant exhibited the least permanent deflection, and the superior negative Poisson's ratio effect, indicating enhanced blast resistance. This work not only contributes to a strategy for designing gradient auxetic cores with enhanced blast resistance, but also provides valuable insights into experimentally understanding the response of complex auxetic configurations under blast loads.

中文翻译：

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具有 3D 打印梯度拉胀芯材的夹芯板在爆炸载荷作用下的动态行为

本研究通过实验和数值研究了由钢面板和 3D 打印梯度拉胀手性芯组成的夹芯板的防爆性能。拉胀芯的设计采用了五种梯度策略，包括均匀梯度、正梯度、负梯度、中心正梯度和中心负梯度。通过调整炸药的质量来施加不同的爆炸载荷。实验中获得了面板和梯度拉胀芯材夹芯板的变形/失效模式。研究了拉胀芯的脉冲和梯度类型对样本动态响应的影响。此外，通过数值模拟阐明了夹芯板的变形过程，并分析了拉胀芯材在充分压缩下的变形模式。结果表明，较高的冲量与面板塑性变形的增加以及拉胀芯内更严重的剪切和拉伸撕裂有关。不同梯度类型的拉胀核心表现出不同的压缩变形行为。其中，负梯度变体表现出最小的永久偏转和优异的负泊松比效应，表明抗爆炸性增强。这项工作不仅有助于设计具有增强防爆性能的梯度拉胀芯材的策略，而且还为通过实验了解爆炸载荷下复杂拉胀配置的响应提供了宝贵的见解。