The principles of fluid flow within circular ducts of seismic dissipation device used in construction systems

Abstract

The intensive development of the construction industry nowadays has made the impressive building projects ideas to become real today all over the world. There has been a constant increase in the height of the building or the opening between supporting pillars if we make reference to bridges or viaducts. These achievements are possible due to the quality of the materials, but also the use of the protection systems, which are designed to provide a good stability degree for structures to which they are mounted in time against the dynamic actions represented mainly by the seismic actions. It is presented in this paper the role of a hydraulic power dissipative system which, by mounting on a building structure has the capacity to limit the structural frames relative displacements induced by the ground seismic motion at a certain moment in time. The dissipation device design is based mainly on a cylinder type with piston and the operation involves the use of a working fluid with special viscosity and compressibility properties. In the case of an earthquake occurrence, the device ends receive the tendency to perform cyclic traction-compression movements involving in motion the piston inside the cylinder. The piston can perform translational movement only based on the forced circulation of the working fluid through the small diameter circular orifices made in the piston head, thus providing a significant energy consumption of the total energy induced by earthquake in the structure. The device's overall model and flow pattern of the working fluid through the piston circular orifices are shown, based on a numerical analysis performed on dissipation device virtual model in order to highlight the flow path-lines of the working fluid that would coincide with the real device model operation.