Creep behavior of full-culm Moso bamboo under long-term bending

Abstract

Bamboo can be easily cultivated and harvested in a relatively short time and has been widely known as a sustainable building material. The study on the long-term creep behavior of full-culm bamboo members is of great significance for the design and use of bamboo structures in engineering, but there are few studies. This paper presents an experimental and numerical study on the creep behavior of full-culm original bamboo beams. In this study, two groups of bamboo beams with different stress levels were analyzed, and the fitting results based on Burger model were obtained. Short-term material properties test was firstly carried out to determine the ultimate strength of Phyllostachys edulis (or Moso bamboo). Secondly, in the creep test, 15 full-culm original bamboo beams were subjected to different constant stress levels for 180 days in an indoor environment, and the creep behavior of bamboo beams was observed and measured over time. Then a creep model of numerical analysis procedure based on the Burger model was established to simulate the creep behavior of each beam. By comparing the numerical analysis results with the test results, basic creep behavior characteristics including creep rate and proportion of each deformation (instantaneous elastic deformation, viscoelastic deformation and viscous deformation) were analyzed and discussed in depth. Finally, the creep behavior of full-culm original bamboo beams was evaluated by the acceptance criteria used for wood and wood-based products. The results indicated that the developed Burger model can well capture the trend of creep behavior including low and high stress level, and the full-culm original bamboo beam under lower stress level has the potential to replace timber in terms of withstanding long-term load. The creep test and numerical analysis of the full-culm original bamboo beams in this paper can provide a reference for follow-up study.