Sliding pendulum isolation system Flexible isolation system suitable for small to large scale buildings Advantages It is possible to set the oscillation period of a building regardless of its weight. High performance seismic isolation can be achieved for light buildings for which conventional methods have been considered impractical. This system can reduce costs not only because of the low cost of the device, but also due to low installation cost. Simple device works well, is easy to install, saves space and is practical for aseismic reinforcement (retrofit). High durability and little chang in characteristics provide stable performance. Maintenance is easy and requires only a simple visual check. Structure FPS is an isolation system consisting of upper and lower spherical plates and sliding puck; the spherical plates have sliding surfaces coated with OILES coating material, and the puck uses OILES skid to reduce friction. Motion of a pendulum The period of a simple pendulum depends on the length of the string, not on its weight. The period of FPS using the pendulum principle can be adjusted by changing the radius of the sliding surfaces. FPS also provides a restoring force due to gravity. In addition, sliding surfaces on the plates provide for significant displacement in a compact device. Movement of OILES sliding material OILES sliding material can absorb and dampen vibration energy as well as alleviating the shock of an earthquake. Basic features This chart shows the relationship between force and displacement when FPS is subjected to extreme deformation as would be expected in a major earthquake. Design values concur closely with physical measurements of performance, demonstrating high accuracy of the design method. Characteristic restoring force of FPS are shown by two lines (bi-linear model). This characteristic makes structural modelling relatively simple. Test Test of contamination by foreign matter Results of testing of the effects of contamination of the FPS on its characteristics (friction factor) showed that performance as an isolation system does not change significantly. Cyclic durability Test Results of a cyclic displacement test applied to an FPS at a speed equivalent to an actual seismic event shows that its characteristics (friction factor) remained stable, indicating good durability.