Cross-laminated timber panel buildings are gaining a growing interest of the scientific community due to significant technical advantages, such as the material sustainability, the high fire resistance and quick constructability. Nevertheless, it is well known that timber panels themselves are not able to dissipate a significant amount of energy during an earthquake. In fact, the design of a Cross-Lam building is carried out in order to dissipate the energy in the steel connections (hold-downs or angle brackets) which govern the seismic performance. The paper here presented proposes to substitute the classical hold-downs, which usually exhibit a limited dissipation capacity, with an innovative type of dissipative angle. The new connection, called XL-stubs, apply the concept usually adopted for designing the hysteretic metallic dampers ADAS (Added Damping and Stiffness). In particular, the hourglass shape allows a better spread of plasticization resulting in a high dissipation capacity. In order to characterize the force-displacement response under cyclic loads of XL-stubs an experimental campaign is carried out comparing the hysteretic behavior of the classical hold-down with that of the proposed dissipative angle.

Massimo Latour, Gianvittorio Rizzano