Numerical study of cross-laminated timber beams using Hill’s yield criterion

Abstract

The computer simulation of wood-based products poses a challenge for professionals in the area, as it is a material with anisotropy, whose properties vary according to the species. Among the wood-based composites is CLT (Cross-laminated Timber), manufactured with lamellae arranged in crossed layers and generally used as an element of walls, slabs and floors. The aim of this work was to analyze the stress distribution in numerical models of CLT beams subjected to three-point bending. Three types of constitutive models were evaluated: the linear isotropic; linear orthotropic; and orthotropic with physical nonlinearities, which is obtained with bilinear curves by Hill's yield criterion. The validation of the numerical models was performed from the experimental load-deflection curves of CLT beams made with Eucalyptus grandis and Toona ciliata (Australian Cedar) loaded until failure. For the simulations, the ANSYS software was used, and the constitutive values of the models were determined from the properties of each lamella. It was concluded that the orthotropic model with physical nonlinearity was closer to the experimental results due to the plastic deformation of the beam. The highest values of von Mises stresses were concentrated at the supports and at the point of application of the load for the Australian Cedar beam, while the stresses were higher in the inner layer of the Eucalyptus beam, due to the rolling shear effect. From the numerical simulation, it was possible to justify the failure modes obtained experimentally.