Journal of Materials Science, special issue on "Materials for Affordable Housing and Infrastructure", (in press) 2005
E. C. N. Silva1, M.C. Walters2 and Glaucio H. Paulino2
1Departmento de Engenharia Mecatrônica e Sistemas
Mecânicos, Escola Politecnica da Universidade de Sao Paulo, Av. Professor Mello
Moraes, 2231, 05508-900; Sao Paulo - SP, Brazil
2Department of Civil and Environmental Engineering, University of
Illinois at Urbana-Champaign,
Newmark Laboraory, 205 North Mathews Avenue,
IL 61801, U.S.A.
Abstract
Natural fibers are promising for engineering applications due to their low cost. They are abundantly available in tropical and subtropical regions of the world, and they can be employed as construction materials. Among natural fibers, bamboo has been widely used for housing construction around the world. Bamboo is an optimized composite that exploits the concept of Functionally Graded Material (FGM). Biological structures such as bamboo have complicated microstructural shapes and material distribution, and thus the use of numerical methods such as the finite element method, and multiscale methods such as homogenization, can help to further understanding of the mechanical behavior of these materials. The objective of this work is to explore techniques such as finite element method and homogenization to investigate the structural behavior of bamboo. The finite element formulation uses graded finite elements to capture the varying material distribution through the bamboo wall. To observe bamboo behavior under applied loads, simulations are conducted under multiple considerations such as a spatially-varying Young's modulus, and averaged Young's modulus, and orthotropic constitutive properties obtained form homogenization theory. The homogenization procedure uses effective, axisymmetric properties estimated from the spatially-varying bamboo composite. Three-dimensional models of bamboo cells were built and simulated under tension, torsion, and bending load cases.
Key words: Bamboo, functionally graded material, homogenization, finite element analysis, graded elements.