The low stiffness resulting from substantial core porosity within the re-entrant honeycomb sandwich panel can be addressed by introducing rib-reinforcements. To investigate its static and vibration characteristics, an energy-based 2D equivalent-homogenization model (2D-EHM) was derived through asymptotic analysis of the leading terms in the governing equations considering the energy-related characteristics. The accuracy of the constructed model for predicting the elastic bending performance of the sandwich panel was verified by comparing the results of a three-point bending experiment with 3D-printed specimens. Comparative analysis with a 3D FE model demonstrates that the 2D-EHM exhibits maximum errors of only 4.65% and 6.46%, respectively, in analyzing static deformation and natural frequency while improving computational efficiencies by up to 59- and 173-folds. Parameter analysis reveals that the performance of SP-RRH is minimally affected by the reinforcement-to-honeycomb wall thickness ratio. However, its performance is compromised when the honeycomb walls align in an equilateral triangle with the reinforcing walls. Comparing specific stiffness as well as static and vibration characteristics of sandwich panels with different core configurations (including traditional and diamond reinforced re-entrant honeycombs) shows that inclusion of rib reinforcements enhances deformation resistance and natural frequencies through increased specific stiffness. These findings provide valuable insights for optimizing design of re-entrant honeycomb sandwich panels.

中文翻译：

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带肋加强凹角蜂窝夹芯板的静态和模态分析

凹进蜂窝夹层板内的大量芯孔隙率导致的低刚度可以通过引入肋加强件来解决。为了研究其静态和振动特性，通过对考虑能量相关特性的控制方程中的主导项进行渐近分析，导出了基于能量的二维等效均匀化模型（2D-EHM）。通过将三点弯曲实验与 3D 打印样本的结果进行比较，验证了所构建的夹芯板弹性弯曲性能预测模型的准确性。与 3D 有限元模型的对比分析表明，2D-EHM 在分析静态变形和固有频率时的最大误差分别仅为 4.65% 和 6.46%，同时计算效率分别提高了 59 倍和 173 倍。参数分析表明，SP-RRH 的性能受钢筋与蜂窝壁厚比的影响最小。然而，当蜂窝壁与增强壁呈等边三角形对齐时，其性能会受到影响。比较具有不同芯结构（包括传统和金刚石增强凹进蜂窝）的夹芯板的比刚度以及静态和振动特性表明，包含肋增强件可通过增加比刚度来增强变形抗力和固有频率。这些发现为优化凹入蜂窝夹芯板的设计提供了宝贵的见解。