Non-conventional Materials and Technologies, Materials Research Proceedings, Vol. 7, pp. 391-402, 2018. Access >>
L.E. Moreira; M. Seixas; J. Bina; J.L.M. Ripper
Abstract: The creep behavior of bamboo culms under long-term loadings was investigated in the present work. Phyllostachys aurea bamboo samples were subjected to four-point flexural creep tests at loads corresponding to 30%, 50%, and 80% of the bamboo's short-term bending strength. Creep and recovery behavior were evaluated for each loading level at room temperature over 398 days, allowing the attainment of primary, secondary, and tertiary creep stages. The failure of one creep test sample occurred at 73 MPa, and the failure mode due to creep was described. Creep mechanisms assessed included node flexibility, cylindrical bending, and shear. Node flexibility contributed 50–74% of total deflection, cylindrical bending contributed 24–48%, while shear contributed less than 2%. A four-element Burgers mechanical model was proposed, matching the experimental results for all loading levels. A viscous coefficient parameter of 4.3 to 30× 103 GPa.day was inferred, corresponding to the linear dashpot n1. These models estimated the bamboo culm deflection over time and predicted failure at a 40% increase in deflection. Overall, this study provided comprehensive insights into the long-term structural behavior of bamboo culms for use in design and engineering applications. This paper presents research results in the structural design and analysis of a selfsupporting
bamboo space structure. The developed structure presents a flexible connection system
and a tensile structural behaviour. The modular frame of the architecture applied hinged lashed
connections (HLC) in textile polyester ropes. The modular frame spans 15m width, 4m length and
7,5m high, using Phyllostachys pubescens bamboo culms. Nonlinear analysis of the structure under
static loadings carried out using the Finite Element Method (FEM) through the SAP 2000 software.
The analysis showed that loads induced by strong winds, overloads and self-weight are relatively low
for the structural members and the developed connections. The results demonstrate that the selfsupporting bamboo space structure meets the requirements of engineering design for safety. This
analysis opens a series of another computational analysis calibrated with mechanical tests to
determine natural frequencies and damping constant for the structure, demonstrating the potential to
be used in earthquake regions.
