Two-dimensional finite element analysis of the flexural resistance of LVL Sengon non-prismatic beams

Abstract

Laminated veneer lumber (LVL) Sengon is nowadays industrialized in Indonesia as an innovative utilization of Sengon wood, a fast growing timber species. The presence applications of this LVL Sengon is very limited yet to simple one-storey dwelling houses, challenges for other structural applications including in the form of non-prismatic members are essential to be discovered. This study evaluates the flexural behavior of laminated veneer lumber (LVL) non-prismatic beams by developing a finite element algorithm that can be implemented in MATLAB software under a plane stress assumption and the assumption that the LVL is an orthotropic elastoplastic material. This algorithm is capable of modeling different values of the modulus of elasticity in both tension and compression, as generally exhibited by timber. The mechanical properties of the LVL was obtained from previous studies, except for its tensile stress–strain relationship. Hill’s yield criterion in combination with an associated flow rule was used in the computation. The numerical results were compared with the experimental data of a previous study that used three non-prismatic (tapered) beams having a length of 4000 mm and cross-sectional dimensions of 200 mm by 200 mm at one end and 200 mm by 400 mm at the other end. The finite element analysis results showed that, after the outermost compression fibers plastically deformed, failure of the beam at the tensile side caused failure of the beam. This phenomenon was also observed in the tests of previous studies.