Viscous dampers (VD), when used in high-rise buildings in seismic areas, should reduce the vibrations induced by both strong winds and earthquakes. Brief Introduction. Viscous dampers generally consist of a cylinder casing, piston, damping hole, damping medium (viscous fluid) and leader. In the event of an. Viscous damping force is a formulation of the damping phenomena, in which the source of damping force is modeled as a function of the volume, shape, and.


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It is a costly approach, as viscous damper entire structure must be supported on elastomeric or sliding bearings.

Viscous dampers distributed throughout an otherwise conventional structure can achieve the same result at significantly lower cost. This paper describes how to install viscous dampers in a structure, and gives several examples.

However it can be costly, and can also involve major building modification. It is now possible to secure a comparable degree of earthquake mitigation with fluid viscous damper dampers located throughout a structure, without having to isolate the building.

This paper describes several techniques for doing this, provides analytical back-up and describes several examples of the application of this technology.

Fluid Viscous Dampers | Seismic Dampers | ITT Infrastructure | ITT Enidine

Summary The next section of this paper describes fluid viscous damping, and shows how it works and how it can benefit a structure. A detailed description of viscous damper typical fluid viscous dampers comes after this, followed viscous damper a comparison of base isolation and fluidic damping as ways to reduce earthquake excitation of structures.


Then comes a discussion of viscous damper and analysis techniques for fluid viscous dampers. The last part of this paper covers case histories like the Stockton City Hall and the Pacific Bell facility.


What Is Fluid Viscous Damping? Fluid viscous viscous damper is a way to add energy dissipation to the lateral system of a building structure.

A fluid viscous damper dissipates energy by pushing fluid through an orifice, producing a damping pressure which creates a force.

These damping forces are 90 degrees out of phase with the displacement driven forces in the structure. This means that the damping viscous damper does not significantly increase the seismic loads for a comparable degree of structural deformation.

Viscous Dampers

This provides a significant decrease in earthquake excitation. Structural dampers are significantly larger than automotive dampers, and are constructed of viscous damper steel and other extremely durable materials as required to furnish a viscous damper of at least 40 years.

The damping fluid is silicone oil, which is inert, non-flammable, non-toxic, and stable for extremely long periods of time. The seals in the fluid viscous damper use viscous damper patented high technology design based on aerospace research, and provide totally leak free service.

This design has been proven through rigorous testing and has been in use for over viscous damper years in both military and commercial applications.

The piston head is made with a deliberate clearance between the inside of the cylinder and the outside of the piston head, which forms an annular orifice See Figure 1. The fluid flows through this orifice at high speed as the damper strokes.

The shape of the piston head viscous damper the damping characteristics.


The exact value for n depends upon the shape of the piston viscous damper. Values of n ranging from. When the fluid viscous damper strokes in compression, fluid flows from Chamber 2 to Chamber 1. When the fluid viscous damper strokes in tension, fluid flows from Chamber 1 to Chamber 2.

The high pressure drop across the annular orifice produces a pressure differential across the piston head, which creates the damping force. As the damping orifice is provided by the annular clearance between the piston head and the cylinder body, it is possible to provide inherent thermal compensation by making these two parts from different materials.