Toughening and Strengthening Mechanisms in Bamboo from Atoms to Fibers

Bamboo, a grass, with stiffness-to-weight and strength-to-weight ratios higher than steel and concrete is a wonder of nature. In this chapter we present a comprehensive review of the mechanical properties of bamboo from nano- to macroscale. After presenting the main toughening mechanisms in bamboo, we present a summary of the atomistic simulations of bamboo microfibril which is the main sources of stiffness and strength in bamboo fibers. The role of humidity in bamboo microfibril is also presented at small scale. It is shown experimentally and numerically that the addition of 1% moisture content to the system does not change density and increases the elastic modulus in the longitudinal direction. This is probably due to the relatively larger fractional free volume in the structure of lignin, and subsequently LCC, at low moisture contents. This interesting phenomenon is important in understanding the mechanics of bamboo microfibrils.