Numerical modelling of the cyclic behaviour of timber-framed structures using opensees


Lukic, Relja; Poletti, Elisa; Vasconcelos, Graça; Rodrigues, Hugo

Simplified FEM; Hysteretic laws; Timber-frame; Opensees

Timber frame structures constitute an important cultural heritage of many countries, since they represent a typical anti-seismic construction adopted worldwide and are worth pre-serving. While these structures have recently been studied experimentally to better understand their behaviour during seismic actions, little studies have been carried out on the numerical modelling of such structures, which could help in improving interventions and retrofitting measures in existing buildings.This paper presents a study on the applicability of numerical models in predicting the global re-sponse of timber-framed shear walls during earthquake events. Based on the in-plane cyclic test-ing of traditional timber frames with and without masonry infill performed in a previous experimental campaign, numerical models were developed that capture the cyclic response of traditional timber frame walls including flexural behaviour, pinching and strength degradation. The numerical models were constructed in the finite element software OpenSees with calibrated springs representing nailed connectors found in traditional half lap joints and based on experi-mental results.A parametric study was conducted on the half-timbered frame model by varying wall configura-tion and studying cumulative energy dissipation and the effect of slenderness and load capacity with increasing drift.All models developed showed a very good approximation of the experimental results, in terms of initial stiffness, maximum load and energy dissipation. Future work includes the development of a macro-model and modelling of a whole timber-framed building in order to improve modelling capacities and predictions.