Shanyu Han, Fuming Chen*, Haidong Li, Ge Wang*

Materials & Design, 2021,212,110254

Herein, inspired by the natural gradient stratification structure theory of the moso bamboo stem wall, a hybrid moso bamboo-poplar veneer composite was developed. In situ scanning electron microscopy (SEM) was employed to characterize the changes in the mechanical behavior of the BWCs under different off-axis tensions in real-time and explore the damage behavior by analyzing the initiation and propagation of cracks in the BWC. The bamboo wall imitation strategy was successful in the preparation of a high-performance biomaterial composite that has significant prospects in the construction industry and there results described herein will help to stimulate new research ideas and develop methods for improving the design and structural properties of thin sheathing panels for building structures.

Fig. 1. Off-axis tensile mechanical properties. (a) Off-axis angle-tensile strength curves; (b) off-axis angle-tensile modulus curves.

The maximum tensile strength and tensile modulus of the BWC were 232.25 MPa and 17.47 GPa, respectively. The maximum specific strength and specific modulus of the resulting BWC were 290.31 MPa·cm3·g−1 and 23.84 GPa·cm3·g−1, respectively（Fig.1）. The failure mechanisms of the BWC under the tension-shear coupling included ductile fracturing and pull-out of the bamboo fibers, as well as brittle fracturing and shearing deformation of the wood fibers (Fig.2）.

Fig. 2. BWC tensile section morphology and its toughening mechanism. (a) distortion and deformation; (b) pull-out and fracturing of the bamboo fiber; (c) glue nail bridging; (d) mechanical interlocking of interlayer.