Numerical Study of Reduction in Vibrations Induced by Water-Pipe System

In certain buildings such as synchrotrons and large ground telescopes, strict requirements are stated regarding the vibration levels. Both external and internal vibration sources, for example traffic and indoor water pumps, can have an appreciable effect on the vibration levels in the buildings. The synchrotron research facility MAX IV, which is currently under construction in Sweden, serves as an example case for the analyses. In MAX IV, several water-pipe systems used for cooling purposes will be placed near vibration sensitive equipment. These systems will transmit vibrations, into structural parts of the facility, which could exceed the vibration requirements. Structural modifications of pipe systems are investigated here by means of the finite element method in order to reduce vibration levels in the building. The finite element model employed includes a water-pipe system, adjacent building parts and the underlying soil. The use of fluid-structure interaction is investigated as well as the use of component mode synthesis. This paper focuses on the numerical procedure used as well as the effects on transmitted vibrations by different placements of the pipe supports.