A Component approach for the hysteretic behaviour of connections in cross-laminated wooden structures

In this paper, a numerical model to estimate the dissipative capacity and describe the cyclic response of cross-laminated (X-lam) timber buildings is presented. The connections between panels and to the foundation (metal hold-downs and angle brackets, and screwed connectors) are modelled with nonlinear hysteretic multispring elements taking into account the strength interaction between different degrees of freedom according to a predefined domain. The timber components (solid X-lam floors and wall panels) are modelled using elastic shell elements. By calibration on experimental cyclic tests carried out on each degree of freedom, important features of timber connection behaviour such as post-peak strength, pinching and stiffness degradation can all be considered. In addition, the effect of friction at the interface between panels and with foundation can be taken into account. These springs have been implemented as external subroutines in a widespread software package such as Abaqus. By comparison with the experimental results of cyclic tests carried out on single X-lam walls, coupled X-lam walls and a single-storey X-lam building, the accuracy of the proposed model is demonstrated.