Estimation of stress–strain curves and elastic modulus of a native Mexican bamboo (Otatea fimbriata Soderstr.)

Among the wide range of natural alternatives to conventional construction materials such as concrete and structural steel, bamboo, a grass species with notable stiffness and strength characteristics, has emerged as a viable option as a structural component in sustainable construction. However, the available information on the physical and mechanical characteristics of the bamboo species growing in Mexico remains limited. Our research characterized the mechanical properties of a native Mexican bamboo species ( Otatea fimbriata ) as a function of its strength, both for normal and bending stress and relating them to their corresponding strain. Data obtained from experimental testing were processed and analysed in accordance with the provisions of ISO 22157:2019 for bamboo structures. The normal strength (in compression) parallel to the fibre and the bending strength parallel to the fibre, as well as the values of the modulus of elasticity and flexural modulus, all of which are essential parameters for the structural design of bamboo-based constructions, were determined. Due to technological and financial constraints, an equation was developed to determine the bending strength of small diameter bamboo culms with low external diameter/thickness ratios, based on data obtained from three-point bending tests. Based on the results, Otatea fimbriata exhibits brittle behaviour in the direction parallel to the fibre and ductile behaviour in the perpendicular direction. This study contributes to the understanding of the mechanical properties of a native Mexican bamboo species from the perspective of sustainable structural design. • An alternative procedure to obtain the elastic modulus of small bamboo species is proposed • The results are compared with the ISO 22157:2019 standard • An expression to obtain the unitary deformation in bending is described • Stress vs. strain curves in compression and bending are shown