Sandwich structures have garnered significant attention due to their high strength-to-weight ratio in various industries, particularly aerospace. Meeting application demands requires optimizing mechanical properties such as bending stiffness, peak load, specific absorbed energy, and weight. This study presents a unique approach involving the design and manufacturing techniques of curved sandwich panels with functionally graded cores, aiming to achieve a comprehensive spectrum of bending properties. Curved structures have applications across diverse fields, including landing gear. The semi-circular core of the sandwich panel comprised three distinct regions defined by angles: Ф, Υ, and 90-Ф- Υ. These angles specified both the location and proportion of different honeycomb cells, including high, medium, and low-density cells. Any variations in these angles and their cell types resulted in a new density gradient. The manufactured sandwich structures consisted of polylactic acid cores printed by a fused deposition modeling printer, sandwiched between aluminum skins. Experimental tests and finite element analysis for three models showed strong agreement, with a maximum error of 14.45%. After the simulation was validated, it expanded to cover other configurations. Subsequently, mathematical models based on the aforementioned angles were calibrated using results extracted from the simulation step. This process led to achieving various structures characterized by a wide range of stiffness (ranging from 0.29 to 0.79 kN/mm), peak load (ranging from 1.73 to 4.77 kN), and specific absorbed energy values (ranging from 41.78 to 96.09 J/kg). The proposed methodology exhibits promise in engineering the design of these structures and their multi-objective optimization.

中文翻译：

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探索具有三维印刷、功能分级芯材的弯曲夹芯板的弯曲行为

三明治结构由于其高强度重量比而在各个行业（尤其是航空航天）中引起了广泛关注。满足应用需求需要优化机械性能，例如弯曲刚度、峰值载荷、比吸收能和重量。这项研究提出了一种独特的方法，涉及具有功能梯度芯的弯曲夹芯板的设计和制造技术，旨在实现全面的弯曲性能。弯曲结构具有跨多个领域的应用，包括起落架。夹芯板的半圆形芯材由三个由角度定义的不同区域组成：Ф、Y 和 90-Ф-Y。这些角度指定了不同蜂窝单元的位置和比例，包括高密度、中密度和低密度单元。这些角度及其细胞类型的任何变化都会导致新的密度梯度。制造的夹层结构由熔融沉积建模打印机打印的聚乳酸芯组成，夹在铝皮之间。三个模型的实验测试和有限元分析显示出很强的一致性，最大误差为14.45%。模拟经过验证后，它扩展到涵盖其他配置。随后，使用从模拟步骤中提取的结果来校准基于上述角度的数学模型。这一过程实现了各种结构，其特点是各种刚度（范围从 0.29 到 0.79 kN/mm）、峰值载荷（范围从 1.73 到 4.77 kN）和特定吸收能量值（范围从 41.78 到 96.09 J/kg） ）。所提出的方法在这些结构的工程设计及其多目标优化方面展现出了前景。