Nonlinear finite element analysis of timber beams and joints using the layered approach and hypoelastic constitutive law

This paper focuses on development and application of finite element models for nonlinear analysis of timber, timber-concrete composite (TCC) beams and joints. A new piecewise continuous orthotropic failure envelope in the bi-axial stress space is proposed for modelling timber behaviour. The proposed orthotropic surface is simplified based on isotropic behaviour of timber along the grains and the model is formulated within the framework of hypoelastic constitutive law. The developed constitutive law and finite element (FE) models are verified by examples taken from the literature including timber beams with and without notches and holes subject to three- and four-point bending as well as push-out test results of TCC connections. Further, the accuracy and performance of the proposed constitutive law for capturing nonlinear behaviour and failure load of timber beams and connections is compared with orthotropic Hashin damage model. The FE results show good agreement with experimental results in terms of load-displacement response and ultimate loading capacity of members and it is concluded that the developed timber model can adequately capture the global as well as the local behaviour of timber beams and TCC connections. (c) 2012 Elsevier Ltd. All rights reserved.