Experimental and numerical evaluations of structural bamboo-based composite materials.

摘要

Due to the shortage and declining quality of wood and environmental pressure on the forest products industry, efforts to optimize the utilization of available forest resources and exploit alternative natural renewable materials are seriously undertaken. This study attempts to demonstrate that Moso bamboo (Phyllostachys pubescens), a species grown well in the U.S., can be one potential material for producing reconstituted composite products, which are popular in the residential and light-commercial buildings construction markets in North America.; Three types of structural bamboo-based composite materials, i.e., (1) strandboard, (2) laminated bamboo-lumber (LBL), and (3) laminated bamboo reinforced southern pine oriented strandboard (LB-OSB) composite beams, are designed and produced with respect to moisture content, panel density, and glue spread rate. Statistical analysis methods and numerical approach, i.e., finite element (FE) simulation are performed.; The experimental results indicated that strandboards possess relatively better properties than commercially-made southern pine OSB panels in terms of modulus of elasticity (MOE), modulus of rupture (MOR), internal bond strength (IB), thickness swelling (TS) and linear expansion (LE). Among the proposed bamboo-based composite products, strandboard can be easily manufactured and transformed to industrial-scale production in existing OSB-type mills. In the point of view of technical feasibility in terms of MOE, MOR, TS, and LE, the LBL is comparable to laminated veneer lumber (LVL) made from commercial wood species such as southern pine, yellow-poplar and sweetgum. However, the processing of bamboo is different from that of wood due to bamboo's special structural characteristics. The procedure is more difficult and the cutting tools wear faster than those in wood production. As a cheaper material, laminated bamboo flanges can significantly improve the flexural behavior of OSB beams. Compared to the evaluation methods, the elastic properties obtained from FE analysis are fairly closed to those from experimental tests. However, the FE simulation gives much more details with respect to the magnitudes and distributions of stresses and displacements within each individual component in the orthotropic wood-based composite materials, especially with a relatively short span because the magnitude of in-plane shear stress, or interlaminar stresses is a major part of total deflection of the composite beam.