Development of a Spring Model for the Structural Analysis of a Double-Layered Timber Plate Structure with Through-Tenon Joints

Timber plate structures with integral mechanical attachments have been successfully built in the last decades. Previous research has highlighted the influence of these connections in the global behavior of the structures. Double-layered plate shells are one of the latest applications of integral joints. Their fabrication and assembly has been proven efficient. However, their structural behavior remains unknown. Simplified models are required to predict their behavior since an individual detailed modelling of the large amount of joints would be time-consuming and computationally expensive. Current simplifications involve either considering the connections as rigid or hinged and do not allow accurate prediction of their behavior. In this paper, a numerical finite element model in which the semi-rigid behavior of the joints is modeled by means of springs is presented for a double-layered timber plate structure made of 5 by 3 segments. The numerical model is automatically generated in the finite element software AbaqusTM from a simplified geometry. Numerical results are compared to a three-point bending test performed on two specimens. The developed spring model shows promising results for its application to a full double-layered timber plate shell. Only axial and shear stiffnesses were implemented in this model while the other degrees of freedom were considered rigid. This consideration might lead to an overly stiff model.