Non linear modelling of timber-concrete composite structures

摘要

The mechanical behaviour of timber-concrete joints has a high influence on the performance of this type of composite structures. Usually the analysis of these structures is done using linear models, assuming linear elastic behaviour for the materials and joints. Nevertheless, the actual mechanical behaviour of most of the timber-concrete joint types, namely the ones made with dowel type fasteners, is rather non linear. Nowadays, material non linear analysis can be easily performed through the use of commercial FEM software packages. Usually the parameters/models required to define the non linear behaviour of the joints are not available, therefore the analysis cannot take it into account. In this paper two models were tried to describe the load-slip behaviour of timber-concrete joints. One of these models was adapted to describe the non linear behaviour of timber-concrete joints made with dowel type fasteners. The model input is based on joint properties obtained from the experimental tests performed in accordance with standard ISO EN 26891, usually followed in the test of this type of joint. The model uses three parameters closely related with the most important joint properties: joint stiffness, joint strength and joint ultimate slip. The load-slip curves obtained with the model are compared with the load-slip curves obtained from the experimental tests, in order to assess the accuracy of the model predictions.