Investigation of the Effect of Inhomogeneous Material on the Fracture Mechanisms of Bamboo by Finite Element Method

Abstract

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.

Exploring the mechanical and morphological rationality of tree branch structure based on 3D point cloud analysis and the finite element method

“…Leveraging the recent growth of 3D reconstruction methods to recover accurate tree structures from 3D point clouds, we aimed to unveil the relationship between the morphological and mechanical properties of trees. First, we hypothesized that the branch-growing process is mechanically unstable in terms of compressive and tensile stresses, and verified it by performing mechanical simulations using the finite element method, which is a similar approach to the recent works 24 , 25 . Using the mechanical results, we constructed a theoretical formulation of tree branch depending on mechanics, shape, and growth based on the axiom of constant stress 6 , 26 .…”

Stress control mechanism by fiber distribution

“…Under bending, buckling can also occur in thin-walled tube. It was observed that bamboo has excellent ability to resist buckling when subjected to bending and shear [23] and local buckling is not considered as a critical mechanism [50]. As local buckling depends on adjusting the slenderness ratio and diameterthickness ratio [51], the tapering structure of bamboo would be the cause of this ability.…”

“…(1) From the ovalization of the cross section, which causes the culm to kink locally, or the Brazier effect [23].…”

A multi‐source information fusion model for safety assessment of bamboo‐integrated products

“…For the simulation-based methods, de Oliveira et al 28 conducted a statistical design to evaluate the effect of the integrated bamboo diameter and the adhesive tape on the maximum load, for which a non-linear Finite Element (FE) analysis is developed to simulate the low-velocity impact test and to predict the failure mechanisms of the skins, bamboo integrated core, and adhesive. Ramful et al 29 used the finite element method to investigate the effect of inhomogeneous material on the fracture mechanisms of bamboo-based materials, and a numerical study of fracture mechanisms in bending, compression, torsion, and shear loadings is finalized. This study's results guide the optimal and safe design of bamboo-integrated products and constructions.…”