Bending failure mechanism of bamboo scrimber

Bamboo scrimber (BS) is becoming one of the most popular engineering bamboo composites because of its excellent physical and mechanical properties. In this study, four-point bending tests in conjunction with in-situ test methods were used to investigate the bending failure mechanism of BS, with nature bamboo (NB) as the reference comparison object. Both the macroscopic and microscopic bending properties were analyzed. Results indicated that the macroscopic load–displacement curves and micro failure morphology of BS showed a typical brittle failure, which was caused by the combined effect of tensile, shear and compressive stress. The elastic modulus of BS was significantly increased due to the increased concentration of sclerenchymatous cells per unit volume. The brittle failure mechanism of BS was shown to be strongly correlated to the compression of main energy absorption tissues contained in the cavities of vessels and parenchyma cells, the composite effect of brittle PF resin filling in the cavities, covering on the parenchyma cell wall and forming glue nails, and the decomposition of hemicellulose. This study was beneficial for the reasonable design and safe application of bamboo scrimber in practical engineering.