关键词: 竹集成材, 格栅夹芯板, 轴心受压, 长宽比, 承载力

Abstract:

Objective: This study aims to explore the axial compression performance of laminated bamboo grid sandwich panels, and propose a calculation formula for axial compression bearing capacity, so as to provide technical reference and theoretical basis for the application of laminated bamboo grid sandwich panels in engineering fields. Method: Four types of laminated bamboo grid sandwich panels with different aspect ratios were fabricated with laminated bamboo as raw material by partition method. In-plane axial compression tests were conducted on the specimens with hinged boundary conditions at both ends. The influence of aspect ratios on the bearing capacity, longitudinal strain, and lateral displacement of the specimens was investigated. Additionally, the failure modes and mechanisms of the specimens with different aspect ratios were examined. The reliability of the experimental results was validated through finite element simulation, and the applicability boundaries of the theoretical calculation formula were systematically delineated via parametric extension analysis. Result: The axial compression process of the laminated bamboo grid sandwich panels was categorized into three stages: elastic stage, elastic-plastic stage, and failure stage. The failure mode of specimens with aspect ratios of 1, 2, and 3 experienced local buckling, while those with an aspect ratio of 4 failed due to global buckling. Compared to the specimen with an aspect ratio of 1, the bearing capacity of specimens with aspect ratios of 2, 3, and 4 decreased by 7.92%, 12.18%, and 18.27%, respectively. The critical load calculation formulas for local and global buckling of sandwich panels, considering the effects of material anisotropy and core shear deformation, demonstrated excellent accuracy. The deviation between the calculated and experimental values of local buckling bearing capacity ranged from 0.86% to 2.83%, while the error between the calculated and experimental values of global buckling bearing capacity was within 8%. Parametric analysis demonstrated that the theoretical calculation formula exhibited high computational accuracy within the aspect ratio range of 1 to 7. The relative errors between the calculated values from the formula, the experimental values, and the finite element simulation values were controlled within 10%. Conclusion: As the aspect ratio increases, the bearing capacity of laminated bamboo grid sandwich panels decreases, and the failure mode changes from local buckling to global buckling. The theoretical calculations for the compressive behavior of laminated bamboo grid sandwich panels demonstrate high accuracy, providing reliable theoretical support for their engineering applications.

Key words: laminated bamboo, grid sandwich panels, axial compression, aspect ratio, bearing capacity