Three-Dimensional Combined Elastic-Plastic and Damage Model for Nonlinear Analysis of Wood

Abstract

This paper presents a three-dimensional combined elastic-plastic and damage model for nonlinear analysis of wood members and connections. A strain-driven implicit algorithm was developed based on plastic theory and continuum damage mechanics, and it was incorporated in the model. The model considers both ductile and brittle wood failures, as well as irreversible deformation and softening behavior of wood. A mesh independence strategy and viscous regularization technique were employed to improve the computation efficiency. The model was tested and validated based on test data. It was found that the irreversible deformation and the softening behavior of wood under compression can be traced by the model with acceptable accuracy. The modeling results of mortise-and-tenon wood connections implied that the proposed model can reasonably predict the strength softening, stiffness degradation, and pinching effect of such connections under reversed cyclic loading. Comparison with elastic-plastic models also indicated that the proposed model was superior regarding the prediction of the connection moment resistance (less than 14.8% error).