Bamboo is a remarkably strong and sustainable material available for construction. It exhibits optimized mechanical characteristics based on a hollow-inhomogeneous structure which also affects its fracture behavior. In this study, the aim is to investigate the effect of material composition and geometrical attributes on the fracture mechanisms of bamboo in various modes of loading by the finite element method. In the first part of the investigation, the optimized transverse isotropy of bamboo to resist transverse deformation was numerically determined to represent its noticeable orthotropic characteristics which prevail in the axial direction. In the second part of this study, a numerical investigation of fracture mechanisms in four fundamental modes of loading, namely bending, compression, torsion, and shear, were conducted by considering the failure criterion of maximum principal strain. A crack initiation stage was simulated and compared by implementing an element erosion technique. Results showed that the characteristics of bamboo’s crack initiation differed greatly from solid geometry and homogeneous material-type models. Splitting patterns, which were discerned in bending and shear modes, differed in terms of location and occurred in the outside-center position and inside-lowermost position of the culm, respectively. The results of this study can be useful in order to achieve optimized strength in bamboo-inspired bionic designs. Recent trends in using sustainable material for building development is reigniting the interest in natural construction materials. Bamboo can be used as a reliable and sustainable alternative to conventional materials in construction based on two key attributes—namely, a high strength-to-weight ratio, and an unrivalled growth rate of up to 100 cm per day [ 1 , 2 , 3 ]. Bamboo morphology has developed into a of smart hollow structure consisting of nodes and internodes which provide the structural framework to support the weight of its uppermost section. As a natural composite, it inherits a high strength-to-weight ratio from a hierarchically arranged microstructure composed of concentrated fibers known as a vascular bundle. The axially strong fibers consist of cellulose microfibrils held in a parenchyma matrix composed of hemicellulose and lignin, as shown in Figure 1 . Furthermore, the volume fraction of vascular bundles increases with height to compensate for the inferior strength of the uppermost section due to the reduced wall thickness. This inhomogeneous structure enables bamboo to withstand extreme flexural loading caused by wind and snow [ 1 , 4 , 5 ]. As a natural material, the strength and durability of bamboo depends on several factors such as species, maturity, treatment and loading conditions [ 6 ]. In construction, the influence of external loading conditions on its strength has high structural implications. Due to its inhomogeneous material characteristics, bamboo displays a complex fracture behavior. Numerous experimental investigations, conducted on deformation behavior due to bending load, have shown mixed failure modes [ 7 , 8 , 9 , 10 , 11 ]. Secondly, the axially strengthened bamboo fibers composed of cellulose microfibrils held in a matrix of hemicellulose and lignin was simplified by assuming a transversely isotropic model [ 36 ]. The microstructure of bamboo nodes consists of thickened vascular bundles which are arranged in an interweaving pattern [ 17 ]. The nodes in bamboo structure have significant structural importance as they improve the lateral stability and stiffness of slender sections and provide additional support to prevent failure by local buckling in the bamboo culm. From Figure 8 , the analysis of results revealed the occurrence of a simultaneous mixed mode of failure at a longitudinal-to-transverse bending stiffness ratio of 100:4.5. The dotted line at this ratio indicates the cross-point at which both innermost and outermost layers have equal resistance to bending deformation. The equal distribution of deformation The maximum principal strain criterion has previously been used to investigate the failure mechanism in engineered bamboo and timber materials [ 48 ], while the maximum principal stress criterion has been considered to investigate the mechanical deformation behavior in bamboo culm sections [ 12 , 25 ]. In this study, the maximum principal strain at failure, ε max , was adopted as the failure criterion in the element erosion setting. The ε max criterion, corresponding to fracture initiation by element erosion, was defined as 30% less than the value of the maximum principal strain. 3.1.1. Firstly, constraints perpendicular to the sliced plane were applied to each model to replicate symmetrical sections. Secondly roller supports were applied at the wall end in bending mode while pin supports were applied at the fixed end in compression and shear modes. Thirdly, deformation was simulated by applying a displacement δ of 5 mm in bending, compression and shear modes, while an equivalent circumferential displacement in terms of torsion angle θ T of 5.73° was applied in torsion mode. 3.1.3. FE Mesh For the purpose of comparing FEM results of bamboo-model, four models were considered in each mode of loading and designing on FEMAP. Both MOE results obtained by the experiment and bending and shear simulation results obtained by FEM showed that bamboo structures have a good capacity to resist transverse fractures, given their optimized strength, which stems from their specific organization structures. This uniquely optimized structure enables bamboo to adapt to bending loads caused by snow or wind while at the same time possessing a structure with a high strength-to-weight ratio [ 17 ]. 3.3.3. Compression In compression, the crack which initiated from the outermost wall of the node-internode section was found to propagate at an angle of 45°, a mode of failure associated with shear band formation [ 13 ].