US 5,491,938 A · High damping structure

Abstract

A high damping device combined with the frame of a building to protect the building from seismic shock. For seismic vibration up to a predetermined level corresponding to the permissible strength of the high damping device, a damping coefficient c of the high damping device is set so as to be c.sub.3 =c=c.sub.1 with respect to a damping coefficient c.sub.3 for giving the maximum value of a damping factor h.sub.3 corresponding to a tertiary mode of vibration of the structure and a damping coefficient c.sub.1 for giving the maximum value of a damping factor h.sub.1 corresponding to a primary mode of vibration. The maximum load on the high damping device is predetermined and means are provided to prevent the high damping device from being damaged in the event that the predetermined maximum load is exceeded. The inventive combination permits the stiffness factor of the building to be reduced from a factor of 1.0 down to a factor as low as 0.3, with a proportionate reduction in steel frame mass.

Claims10

Dependent claims

In combination, a multi-storied structure having column and beam frame members;

earthquake-resisting braces secured to and reinforcing said frame members;
non-variable, self-contained passive hydraulic damping devices secured between said frame members, or between one of said frame members and one of said earthquake-resisting braces, or between said earthquake-resisting braces on the individual stories of said multi-storied structure, said passive hydraulic damping devices being energized solely by seismic vibrations impacting on said frame members to independently passively damp said seismic vibrations up to a predetermined level;
and fail safe means to prevent vibration overload on said non-variable, self-contained hydraulic damping devices, said non-variable, self-contained hydraulic damping devices having predetermined non-variable damping coefficients preselected and preset to provide damping factors within predetermined ranges.

In combination, a multi-storied structure having column-and-beam frame members;

earthquake-resisting braces secured to and reinforcing said frame members;
and passive hydraulic damping devices secured between said frame members or between one of said frame members and one of said earthquake-resisting braces or between said earthquake-resisting braces;
said structure having natural modes of vibration V.sub.1, V.sub.2 and V.sub.3 wherein a damping coefficient c.sub.1 provides a maximum damping factor h.sub.1, a damping coefficient c.sub.2 provides a maximum damping factor h.sub.2, and a damping coefficient c.sub.3 provides a maximum damping factor h.sub.3, in which the relationship of said coefficients is c.sub.1 .ltoreq.c.sub.2 .ltoreq.c.sub.3 ;
means to provide said hydraulic damping devices with a fixed preset damping coefficient c.sub.2 set at a predetermined level;
means to preset said hydraulic damping devices to prevent overloading by seismic vibrations exceeding a preset predetermined level;
and means to maintain said damping coefficient c.sub.2 at said fixed preset predetermined level.

3 more elements

Dependencies are inferred from the claim text.

High damping structure

Life of this patent

High damping structure

Life of this patent

Abstract

Claims10