Improvement of seismic performance of precast frames with cladding panels fastened by energy dissipative steel cushions

Precast reinforced concrete panels are commonly used as wall claddings in precast buildings. The cladding panels are generally evaluated as non-structural members and are joined to structural systems via mechanical, welding, and bolted dry connections. Several failures were observed in the last seismic events in Southern Europe, which demonstrate the deficiencies of the cladding connections in terms of strength and ductility. A comprehensive research activity named SAFECLADDING was conducted in Europe to provide knowledge for proper seismic design of precast structures with cladding panels. In this context, energy dissipative steel cushions were developed and evaluated through the extensive experimental and numerical studies. Steel cushions can provide robust interaction of the structural system with the cladding panels. This paper numerically evaluates the effects of cladding panels with steel cushions on the global seismic behaviour of the buildings. An existing representative industrial building is selected to perform intensive nonlinear dynamic analyses. Analyses performed on the bare and hybrid systems showed that the hybrid system has high performance in terms of story drifts, internal forces, and deformations with respect to the bare system. The overall drifts in longitudinal and transversal directions of the building are reduced by about 78 and 54%, respectively. Average residual drifts of cladding panels and steel cushions indicated that the applied steel cushion placement scheme has a promising re-centring capability during seismic action. The research presented herein was accomplished via the valuable experimental and numerical data derived FP7 project, "SAFECLADDING: Improved Fastening Systems of Cladding Wall Panels of Precast Buildings in Seismic Zones" research for SME associations, grant agreement number 314122, coordinated by Mr. Alessio Rimoldi from BIBM, Belgium. The financial support provided by the Commission of the European Communities through SAFECLADDING and other project partners are greatly acknowledged. The study was conducted at the Structural and Earthquake Engineering Laboratory (STEELab) of Istanbul Technical University. Support for the laboratory staff and graduate students is gratefully acknowledged. Publisher's Version