Numerical Modelling of Drying Induced Cracks in Wood Discs Using the Extended Finite Element Method

Abstract

Drying crack is a common phenomenon occurring during moisture discharge from wood, reducing efficient wood utilization. Drying crack is primarily caused by drying stress, and the reasonable methods for determining drying stress are sparse. In this study, the initiation and propagation of cracks during wood discs drying were simulated using the extended finite element method (XFEM). The distribution of drying stress and displacement was analyzed at different crack conditions based on the simulation results. This study aimed to solve the problem of the limitation of drying stress testing methods and provide a new idea for the study of wood drying stress. The numerical simulation results are found in good agreement with the experimental results, thus corroborating the feasibility of XFEM in modeling drying crack of wood discs. The stress concentration was observed at the crack tip region, while a minor stress was presented in the region of crack passing through, indicating that the crack formation process was also a process of releasing drying stress. Further, more energy was required to form double cracks in comparison with the single crack mode.