Dynamic behavior of a two-storey cross laminated timber mockup

Timber constructions have gained an increasing attention in the last years, due to the limited installation time and the reduced expertise in manpower required, since panels assemblage is mainly based on dry mounting techniques. Among these, Cross Laminated Timber (CLT) products are extensively used in constructions, as they allow to overcome the main weaknesses of hardwood artifacts. Moreover, CLT components are also being tested within the restoration and re-use of existing buildings. Since these timber products are relatively new in the construction market, experimental data and site investigations are still limited and some aspects still unknown. Among the many, dynamic characterization of CLT structures, and related model updating, is rare in literature. In such a context, an experimental campaign aimed at assessing the linear dynamic behavior of CLT structures was carried out. A building-scale specimen (mockup) was constructed; it was made of C24 CLT walls and diaphragms (floor and roof) with 10- and 14-cm thick panels, respectively, connected through steel brackets and screws. The mockup was investigated via dynamic identification tests, by implementing 12 piezoelectric accelerometers, i.e., 4 on the first floor and 8 on the roof. The experimental characterization was aimed at: (i) assessing the structural dynamic behavior and identifying the role of structural details on it; (ii) evaluating the experimental stiffness, compared to analytical predictions. At last, a finite element (FE) model was implemented and updated based on the experimental outcomes.