Longitudinal compression constitutive model of original bamboo and buckling simulation of bamboo column

The longitudinal compressive properties and stress–strain relationship of original bamboo at different culm heights were studied by a uniaxial compression experiment. The experimental results show that the failure mode of bamboo is bulging failure, and its ultimate compressive strength increases linearly with the increase of height at the bamboo culm. The longitudinal compressive stress–strain curves of bamboo at different heights are normalized, and the three-stage nonlinear constitutive model and the Boltzmann constitutive model are established. The two models are close to the experimental results and can describe the main stages of bamboo compression. A finite element model of the compression specimen is established to verify the accuracy of the proposed constitutive model, and bamboo column models with different slenderness ratios are established to evaluate the feasibility of the proposed constitutive model in buckling analysis. The results show that the finite element model can well simulate the buckling capacity of the bamboo column after introducing the initial defect of L/500, while the slenderness ratio is greater than 30. This work is expected to be useful for the finite element analysis of bamboo and prediction of buckling capacity of original bamboo columns.