Long-term tensile behaviour of engineered wood in parallel to grain direction

Abstract

Long-term behavior of engineered wood species was investigated under tensile loading in variable outdoor climatic conditions. Sustained tensile loads parallel to the grain were applied to specimens of Spruce Pine, Pacific Teak, Laminated Lumber Veneer, and Cross-Laminated Timber. Tests were conducted at three different stress levels simultaneously and temperature and relative humidity of the environment were monitored continuously throughout the loading period. A constitutive fiber finite element model was developed to simulate the experimental data. Complementary data for free shrinkage and swelling as well as diffusion coefficient from the same samples were measured in three orthogonal directions and the generated model was calibrated. The developed constitutive model considers the effect of viscoelastic and mechano-sorptive creep, shrinkage and swelling, thermal and moisture inelastic deformation, and deformation due to Young's modulus changes. There is a good correlation between the numerical and experimental results. © WCTE 2018 Committee.