Effect of moisture content, heating time and temperature on the bending mechanical properties of Phyllostachys iridescens

Round bamboo is easy to be bent at high temperature. However, there’s a dearth research on bending properties of round bamboo in heating state. In order to investigate the optimal bending parameters in thermal treatment of round bamboo, this study assessed the influence of heating temperature, duration, and moisture content on the bending properties of round bamboo by examining the modulus of elasticity (MOE), modulus of rupture (MOR), and displacements. The findings indicated that the temperature of 160 °C could be considered as a priority, as it resulted in a 67.7% decrease in MOE, a 50.8% decrease in MOR, a 134% increase in elastic displacement (D_e), and a 160% increase in plastic displacement (D_p) compared to the control. Heating durations ranging from 5 to 15 min may be suitable for balancing cost and efficiency. Moreover, a moisture content (MC) exceeding 10% was found effectively to enhance the bendability of round bamboo. Specifically, when MC increased from 0 to 45%, the MOE decreased by 85.6%, the MOR decreased by 68.3%, D_p increased by 8.3%, and D_e increased by 110.3%. Based on these results, it can be inferred that round bamboo with MC above 10%, heated at 160 °C for a duration of 5 min to 15 min, can be easily bent.