Modeling of post-tensioned timber framed buildings with hysteretic bracing system: preliminary analysis.

The increasing demand for multi-storey timber framed buildings in seismic areas has led to the developing of damage limiting systems. The self-centering rocking mechanisms combined with dissipative systems, such as dissipative bracing is a high-performance system that can prevent major structural damage and minimize residual drifts during strong earthquakes. This paper shows the modelling of a three-dimensional, three-storey, two-third scaled, post-tensioned timber framed model equipped dissipative bracing systems and compares the numerical simulations with the experimental results obtained at the structural laboratory of the University of Basilicata. The hysteretic bracing system is composed by V-inverted timber brace in series with U-shaped flexural steel plates. During preliminary shaking table tests, the specimen was subjected to two earthquake inputs at different intensity levels. The braced model was developed using an appropriate combination of elastic elements with lumped rotational and linear springs, by means of two different software OpenSees and SAP2000. Both numerical outcomes of nonlinear dynamic analysis are in good agreement with the global and local seismic experimental response of the braced model and of the hysteretic dampers. Based on the validation of the numerical models further studies of optimization of design methods and a complete probabilistic characterization of Pres-Lam building performances will be developed