| dc.description.abstract | One of the most common ways to conceive seismic-resistant steel structures is by adopting the
Moment Resisting Frames (MRFs). This approach ensures that the building withstands the seismic
event through the development of plastic hinges at the beam ends, beam-to-column connections or
column bases. The most widespread design philosophy relies on the strong-column strong-connection
weak-beam approach, which ensures the development of plastic hinges only at the beam ends and
first-floor column bases. Nevertheless, this approach implicitly accepts the development of structural
damages during a severe seismic event to dissipate the input energy. This is a negative aspect because
it affects the reparability and functionality of buildings.
For this reason, in the last decades, as an alternative to this classic design strategy relying on full-
strength joints, a new design philosophy based on the use of partial-strength beam-to-column
connections was developed. This method relies on the strong-column weak-connection strong-beam
approach so that the dissipation of the seismic input energy occurs only in well-defined nodal
components, which can be easily substituted at the end of the earthquake. In such a way, structural
resilience is also achieved.
Several traditional and innovative solutions have been proposed and investigated within this
framework. These beam-to-column joints have been widely studied based on experimental tests,
numerical simulations, and theoretical formulations deriving from adequately defined analytical
models. In particular, the experimental tests and the corresponding simulations have regarded beam-
to-column sub-assemblies under monotonic or cyclic loading histories. In such a way, the basic
information related to the analysed joints’ stiffness, resistance, ductility and energy dissipation
capacity could be easily derived. Instead, very few tests on large-scale steel structures subjected to
seismic inputs have been performed.
In this framework, a relevant research programme has been planned at the University of Salerno. It
aims at assessing the dynamic behaviour of different beam-to-column connections over the seismic
response of large-scale structures. In particular, a significant part of this investigation relates to
performing pseudo-dynamic tests on a mock-up building equipped with different traditional and
innovative joints: the Reduced Beam Section (RBS or dog-bone) connection; the FREE from
DAMage (FREEDAM) joint; the double-split dissipative T-stub (or X-shaped) connection.
The configurations mentioned above represent joints connecting double-tee beam and column
profiles, reflecting possible American and European applications. However, since there is widespread
use in Japan of tubular columns, configurations connecting hollow sections and double-tee profiles
should not remain unexplored. Under this perspective, this thesis also focuses on the static
characterisation of joints connecting circular-hollow-section (CHS) columns and through-all double-
tee beams by adopting the component method approach. At the moment, the most common way of
conceiving such a kind of joint consists of simply welding the beam to the external surface of the
column or using collar plates or composite solutions. However, these alternatives do not ensure
relevant mechanical properties and simply structural detailing of the connections. Instead, the recent
technological advancements introduced the possibility of using 3D Laser-Cutting for manufacturing
the joint mentioned above, whose peculiarity is that the beam can intersect the column, enhancing the
mechanical properties but with simple nodal detailing. Therefore, the need to study this connection’s
behaviour through the component method approach relies on the possibility of employing this joint
together with other solutions (i.e. RBS, ...).
However, because of the incompatibility between the profiles of the columns, the seismic response
of this connection cannot be investigated through the same mock-up building used to perform the
pseudo-dynamic tests. For this reason, at the end of this thesis, a preliminary and brief introduction
to the hybrid simulations with dynamic substructuring technique is reported. [...] [edited by Author] | it_IT |
