Glass facades under seismic events and explosions: a novel distributed-TMD design concept for building protection

Glazing facades generally represent one of the most critical building components, from a structural point of view, since providing a physical separation and barrier for the building occupants. In this regard, especially under the action of extreme loads, they require specific design concepts voted to protect the building occupants. In this paper, the feasibility and potential of special mechanical connectors interposed at the interface between a given multi-storey primary building structure and the glazing facade are investigated via accurate finite-element models, under the action seismic and explosive loads. Given the case study of a 4-storey steel framed structure enclosed by a glazing curtain wall, both the global and local effects and potential benefits due to additional vibration control systems (VCSs) are preliminary assessed via numerical simulations, giving evidence of the activation—once properly designed—of a distributed-tuned-mass damper (TMD) concept involving the glass facade as a structural component of the 3D building. Differing from traditional TMD applications in civil engineering systems—namely consisting of lumped mass, damping and stiffness terms—these beneficial contributions are derived from the enclosing glass panels. Taking advantage of earlier research studies, in particular, where major efforts have been spent for the potential of visco-elastic VCSs, careful consideration is paid in this paper for the feasibility of elasto-plastic (PL) connectors, giving evidence of their response and effects under both seismic events and explosions. As shown from FE results partly discussed in the paper, the full 3D assembly can take benefit from the proposed design concept, hence suggesting the further development of the explored passive mitigation tool for the protection of the primary building structure.