New earth quake damper for buildings

Important results from the project

The aim with the project was to determine the possibility to use wire rope isolators as seismic earth quake dampers for buildings (as stand alone solution or in combination with for example steel springs). The main focus during this project has been on the wires itself, to analytically and practically examine if the properties are suitable for the application as seismic dampers. Through a number of tests and calculations we have concluded that the concept works. A small prototype has also been made.

Expected long term effects

The results from the project show that the concept with wire can indeed work as seismic damper. The wire has enough internal damping and the needed stiffness can be acquired within reasonable dimensions (comparing with existing products on the market). The damper will be completely made of metal and will therefore not be affected by changes in temperature or by sunlight, it will not age and change characteristics - and it will be completely recyclable. Before it can be considered a commercial product further FE-analysis and more comprehensive tests (on a bigger prototype) have to be done.

Approach and implementation

With the goal of finding a new type of earth quake damper for buildings we have examined the properties of wires and how these might be combined with low friction materials. The tests have been done both in tension and compression, in three different directions, with different wire diameters and with different loop diameters. The test results have led to a mathematical model where values for other non-tested diameters (on wire and loop) can be extrapolated. Based on this a preliminary damper has been designed, resulting in dimensions 0,9 x 0,9 m and a stiffness of 2-3 MN/m (non-linear).