The work presented is aimed at the investigation of the influence of beam-to-column connection typologies on the seismic response of MR-Frames designed according to the Theory of Plastic Mechanism Control (TPMC). The investigated typologies are four partial strength connections designed in order to obtain the same flexural resistance. The first three joints are partial-strength semi-rigid connections while the fourth one is a beam-to-column connection equipped with friction pads properly designed to assure the earthquake input energy dissipation. Beam-to-column joints are modelled by means of rotational inelastic spring elements located at the ends of the beams whose moment-rotation curve is characterized by a cyclic behaviour accounting for stiffness and strength degradation and pinching phenomenon. The parameters characterizing the joints cyclic hysteretic behaviour have been calibrated on the base of experimental results aiming to the best fitting. The prediction of the structural response has been carried out by means of IDA analyses.
Dissipation
INNOVATIVE CONNECTIONS FOR TIMBER PANEL BUILDINGS
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.