Investigation on the shear performance of steel-bamboo composite beams with web opening

This paper proposes a new type of steel-bamboo composite beam with web opening, so as to expand the application direction of steel-bamboo composite beams, and also to exploit the application superiority of web-opening techniques. Tests and finite element analysis were conducted on steel–bamboo composite beams with web openings to investigate the effects of parameters such as bending–shear ratio, cross-sectional area, and height, size, and shape of the web opening on the failure characteristics and force transfer mechanism of the composite beams. The main factors affecting the stress performance were analyzed and a theoretical method for calculating the ultimate shear capacity of the steel–bamboo composite beams was derived. The results showed that the shear capacity and stiffness of the composite beams decreased significantly after incorporating the web opening, and failure occurred in the area containing the opening. The ultimate shear capacity of the composite beams was positively correlated with the height of the web and inversely correlated with the bending–shear ratio in the area of the opening. Increasing the steel area obviously increases the ultimate shear capacity, followed by the incorporation of the bamboo web and bamboo flange. The web opening parameters (size and shape) directly affect the mechanical properties of the steel–bamboo composite beams, opening should be selected as long and narrow as possible. The theoretical values of the ultimate shear capacity showed good agreement with the experimental values, thus verifying the effectiveness of the proposed calculation method.