Monotonic tests on beam-to-column joint with steel link for timber seismic resistant structures

Abstract

For the design of dissipative heavy timber frame structures, in the context of modern seismic design approach based on the mechanical triad of strength, stiffness and ductility, brittle timber failure modes can be avoided by integrating modern timber connection technology into hybrid timber-steel system. The overall seismic performance can be improved, entrusting the dissipation function to ad hoc conceived devices, as an alternative to connections. Steel links located at the ends of the beams are very promising solutions, which can develop plastic hinges, thus providing a ductile behaviour, with a significant dissipative capacity. Besides timber members, as well as connections, to be designed with an adequate over-strength, can remain in elastic field. In this perspective, the paper illustrates the mechanical characterisation through monotonic tests of two different configurations of timber beam-to-column joint with steel link for heavy timber frames, consisting of a timber element connected to a steel link by means of a steel end-plate and glued-in steel rods. The experimental results indicate a satisfactory agreement with the theoretical ones, therefore the suitability of the system and of the design criteria.