Preparation and mechanical properties of corrugated bamboo bundle laminated composites

A novel bamboo bundle laminated composite(CBLC) with a corrugated structure was developed. Three types of stacking sequences including type Ⅰ (0°)₆, type Ⅱ (0/90°)₃ and type Ⅲ (90°)₆ were designed. The effect of stacking sequence on the properties of tension, biaxial bending and 3D compression were investigated, meanwhile, the strain fields under bending load were characterized by digital spackle correlation method (DSCM). It has been found that the behaviors of tension, bending and compression are effected significantly by stacking sequence of composites with type Ⅰ > type Ⅱ > type Ⅲ for the stretching and vertical bending tests, and type Ⅱ > type Ⅲ > type Ⅰ for the lateral bending performance. The fracture mechanisms under tensile process are dissimilar, which are controlled by stacking sequences. Type Ⅰ shows a ductile fracture model, type Ⅱ displays a gradual delamination and type Ⅲ illustrates a brittle failure. Strain-fields in x and y direction mainly concentrate at the outermost layer near the bottom of corrugated wave connection with E_xx < E_yy. Multiple comparisons show that the compressive properties of CBLC are significantly different in the three dimensions with y > x > z. The stacking sequences have a significant effect on the compression loading and strength, except for compression modulus.