Variation in the Cell Wall Mechanical Properties of Dendrocalamus farinosus Bamboo by Nanoindentation

The in situ imaging nanoindentation technique was used to investigate the effect of age, culm height, and radial position on the cell wall mechanical properties of bamboo (Dendrocalamus farinosus) along the longitudinal direction of culms. The results indicated that among our four-sampled culm ages, the fiber cell wall had average values for the elastic modulus (MOE) and hardness (HL) of 18.56 GPa and 410.72 MPa, respectively. The ages of the culm had no significant effect on the observed MOE and HL among the 2-, 3-, 4-, and 5-year-old D. farinosus test specimens, with similar results observed at three different culm heights and radial positions. Furthermore, longitudinal MOE and HL values along the thickness of the cell wall were uneven, with average values for the middle lamella and the edge near the cavity only 20.97% to 29.78% and 9.22% to 31.71%, respectively, of the values found in the cell wall.