Objective Integrated bamboo has low utilization efficiency and is used in a rather limited variety of forms in engineering applications. So exploring advanced structural forms that integrate the lightweight and high-efficiency characteristics of bamboo is of great significance in promoting the application of bamboo in the field of engineering. This study aims to investigate the impact of different lattice configurations on the bending performance of laminated bamboo sandwich panels, select the structure with the best bending resistance among various lattice configurations, and provide a theoretical basis for its application in practical engineering.

Method Three kinds of laminated bamboo sandwich panels with different lattice cores, namely triangular lattice, square lattice and Kagome lattice, were designed and processed with laminated bamboo as raw material by interlocking method in this study. A four-point bending test was carried out on laminated bamboo sandwich panels with different lattice cores, and the bending performance of sandwich panels was discussed. The failure mechanism of sandwich panels under bending load, as well as the variation law of mid-span deflection, bending stiffness and ultimate bearing capacity, were analyzed, and the specific strength and specific stiffness of laminated bamboo sandwich panels with three different core layers were compared. At the same time, a four-point bending test model of laminated bamboo sandwich panels was established by finite element method, and numerical simulation was carried out.

Result Three kinds of sandwich panels with different lattice cores all showed shear failure during the bending loading, among which the triangular lattice sandwich panel had the best bearing capacity. Compared with square lattice sandwich panel with ultimate bearing capacity of 22.5 kN, the ultimate bearing capacity of sandwich panels with triangular lattice and Kagome lattice was 38.7 and 27.5 kN, increased by 71.9% and 22.2%, respectively. The specific strength of laminated bamboo sandwich panel with triangular lattice was 133.5 kN·m/kg, which was 41.2% and 38.1% higher than that of square lattice and Kagome lattice with specific strength of 94.6 and 96.7 kN·m/kg, respectively. The finite element model was in good agreement with the test results, which can effectively predict bending performance of laminated bamboo sandwich panels.

Conclusion Among the three kinds of lattice cores, the laminated bamboo triangular lattice sandwich panel has the best bending performance, which can better present the lightweight and high-strength advantages of laminated bamboo. The research results can provide an effective structural form and theoretical basis for the application of bamboo in the engineering field.