G. PIANESE(1), G.MILANI(1) and A. FORMISANO(2)
(1) Department of Architecture, Built environment and Construction Engineering, Politecnico di Milano, Milano, Italy
gaetano.pianese@polimi.it , gabriele.milani@polimi.it
(2) Department of Structures for Engineering and Architecture, University of Naples Federico II, Naples, Italy,
ABSTRACT
Many developing countries are located in earthquake-prone areas where buildings are often of poor design and not sufficiently protected against earthquakes. This causes damage or total collapse of buildings and heavy casualties whenever an earthquake occurs. Elastomeric isolators are special devices for the seismic isolation of structures. Typically, they consist of alternate layers of steel or fiber-reinforced laminas and rubber. They are positioned between the ground and the foundation to increase the structure’s natural period and reduce the inertia forces applied in case of an earthquake.
This study proposes a detailed 3D Finite Element (FE) modelling of elastomeric isolators for low-rise masonry buildings in developing countries, developed with the FE software code Abaqus.
The isolator consists of an energy dissipation core made of relatively High Damping Rubber and an external Ethylene Propylene Diene Monomer (EPDM) ring. In addition, it presents unbonded boundary conditions to reduce production costs and allow its applicability in developing countries. The upper and lower edges do not exhibit any bond with the supports. The main feature of such a device is the large deformability thanks to the roll-over deformation and the favourably lower lateral stiffness compared to the bonded isolator.
KEYWORDS: seismic isolation; fibre-reinforced elastomeric isolator (FREI); high damping rubber; regenerated EPDM; non-linear dynamic analysis.