sliding pendulum isolators - Antiseismic devices - Algasism APS
ALGAPEND seismic isolators are the result of the most
updated technology. They have been developed starting
from an idea born in the USA in the 1980's implemented
by the most updated research in the field of synthetic materials
with low or controlled friction.
Their main characteristics are the following:
• They allow the relative displacement of the structure in
respect of the foundations following one or two spherical
surfaces.
• The radius of the spherical surfaces determines the natural
period of the structure.
• The natural period is practically independent from the
mass of the structure.
• The friction coefficient of the sliding surface determines
the equivalent friction damping of the isolation system
ALGAPEND isolators are based on the application of a series
of sliding materials called HOTSLIDE, which are the result
of a research program appointed by ALGA to the Politecnico
di Milano and protected by international patent.
The HOTSLIDE controlled friction materials have the following
particular characteristics:
• Controlled friction coefficient means that the actual friction
will correspond to the specified one within a narrow
tolerance. Furthermore, friction will not be affected by the environmental
temperature.
• HOTSLIDE sliding materials have an outstanding resistance
to wear and to high temperature. These properties make
them particularly suitable as energy dissipating elements
based on friction with exceptional performance.
• HOTSLIDE sliding materials have a very high characteristic
compressive strength, more than twice that of PTFE.
Therefore it is possible to greatly reduce the dimensions
of the devices with a cost saving design.
ALGAPEND isolators may be designed following three basic
types:
1. With one main spherical sliding surface, that may be
at the top or at the bottom of the device, connected to a
spherical hinge.
2. With two main spherical surfaces with an interposed point
rocker articulation. (This solution is protected by an international
patent). With this feature it is possible to minimize
the dimensions in plan of the isolator and the eccentricity
caused by the horizontal displacement.
3. With two perpendicular cylindrical surfaces, one on top
and the other at bottom, with two perpendicular cylindrical
articulations interposed. (This solution is protected by
an international patent). With this solution, properly selecting
the friction materials, it is possible to have two different
behaviours of the device in the two perpendicular
directions.
