Viscoelastic bracing damper

Abstract

The present invention relates to a viscoelastic bracing damper (100), comprising: a cylinder (101); an inner core (102) extended through the cylinder (101) without contacting an inner surface of the cylinder (101), thereby having a barrel portion formed between the inner surface of the cylinder (101) and the inner core (102); a joint (103) connecting a front connector (104) to one end of the inner core (102); a stopper (105) connecting an end connector (106) to an another end of the inner core (102); and characterised by a damping means (107) extended substantially along a length of the barrel portion; wherein the damping means (107) is compressed between the inner surface of the cylinder (101) and the inner core (102) for absorbing vibration loads.

Claims

1. A viscoelastic bracing damper (100) for attaching to a pair of diagonally-opposed beam-column joints of adjacent floors of a building structure to absorb dynamic or vibrational loads caused by wind or an earthquake, the viscoelastic bracing damper (100) comprising: a cylinder (101); an inner core (102) extending through the cylinder (101) without contacting an inner surface of the cylinder (101), thereby forming a barrel portion between the inner surface of the cylinder (101) and the inner core (102); a joint (103) connecting a front connector (104) to one end of the inner core (102), the front connector (104) being for connecting the viscoelastic bracing damper (100) to one of the pair of beam-column joints of adjacent floors of the building structure; a stopper (105) connected to an opposite end of the inner core (102) and passing through an opening in an end connector (106) to limit excess lateral movement of the building structure during vibration, the end connector (106) being for connecting the viscoelastic bracing damper (100) to the other of the pair of beam-column joints of adjacent floors of the building structure; and a damping means (107) extending substantially along a length of the barrel portion; wherein the damping means (107) is compressed between the inner surface of the cylinder (101) and the inner core (102) for absorbing vibration loads and is bonded to the inner surface of the cylinder (101) and to the inner core (102).

2. The viscoelastic bracing damper (100) according to claim 1, wherein the damping means (107) is a viscoelastic material.

3. The viscoelastic bracing damper (100) according to claim 2, wherein the viscoelastic material comprises rubber.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The features of the invention will be more readily understood and appreciated from the following detailed description when read in conjunction with the accompanying drawings of the preferred embodiment of the present invention, in which:

(2) FIG. 1 shows a viscoelastic bracing damper;

(3) FIG. 2 shows an exploded view of the viscoelastic bracing damper in FIG. 1.

(4) FIG. 3 shows viscoelastic bracing damper installed to a frame structure;

(5) FIG. 4 shows a steel bare frame structure;

(6) FIG. 5 shows a graph of reaction force with applied displacement for steel bar frame structure subjected to lateral cyclic load in FIG. 4;

(7) FIG. 6 shows a steel frame with chevron bracing structure subjected to lateral cyclic load;

(8) FIG. 7 shows a graph of displacement with base shear for steel frame with chevron bracing structure subjected to lateral cyclic load in FIG. 6;

(9) FIG. 8 shows a steel frame with viscoelastic bracing damper subjected to lateral cyclic load;

(10) FIG. 9 shows a graph of base shear with displacement for steel frame with viscoelastic bracing damper in FIG. 1 subjected to lateral cyclic load in FIG. 8.

DETAILED DESCRIPTION OF THE INVENTION

(11) As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting but merely as a basis for claims. It should be understood that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the invention is to cover all modifications, equivalents and alternatives falling within the scope of the present invention as defined by the appended claims. As used throughout this application, the word “may” is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words “include,” “including,” and “includes” mean including, but not limited to. Further, the words “a” or “an” mean “at least one” and the word “plurality” means one or more, unless otherwise mentioned. Where the abbreviations or technical terms are used, these indicate the commonly accepted meanings as known in the technical field. The present invention will now be described with reference to FIGS. 1-9.

(12) The present invention presents viscoelastic bracing damper (100), comprising: a cylinder (101); an inner core (102) extended through the cylinder (101) without contacting an inner surface of the cylinder (101), thereby having a barrel portion formed between the inner surface of the cylinder (101) and the inner core (102); a joint (103) connecting a front connector (104) to one end of the inner core (102); a stopper (105) connecting an end connector (106) to an another end of the inner core (102); and characterised by a damping means (107) extended substantially along a length of the barrel portion; wherein the damping means (107) is compressed between the inner surface of the cylinder (101) and the inner core (102) for absorbing vibration loads.

(13) In a preferred embodiment of the present invention, the damping means (107) is a viscoelastic material comprises rubber such as isoprene, ethylene propylene diene (EPDM) or polybutadiene.

(14) In a preferred embodiment, the viscoelastic material is mounted between the inner core (102) and cylinder (101) and bonded to both surfaces as energy dissipator members to absorb vibration loads.

(15) According to the present invention, the front connector (104) and end connector (106) comprises hinges for installation the viscoelastic bracing damper (100) to a structure or bridge joints. The stopper (105) is connecting the end connector to one end of inner core (102) for limiting the excess lateral movement of structure under any source of excitation or vibration.

(16) During structural movement, the vibration is transferred from structure joints to the hinge connection of viscoelastic bracing damper (100) and cause the inner core (102) to move within the cylinder (101). The damping means (107) between the inner core (102) and cylinder (101) dissipates the vibration effect by shear stiffness and damping action of the damping means (107).

(17) The resistant and damping force of viscoelastic bracing damper (100) is depend on properties of the damping means (107) between the inner core (102) and the cylinder (101). The damping means (107) is compressed between the inner surface of the cylinder (101) and the inner core (102) to reduce inter-story drift due to imposed lateral vibration. The damping means (107) increases the shear stiffness so as to increase the shear resistant force.

(18) In a preferred embodiment, the viscoelastic bracing damper (100) is not limited to be used for building, vessel, vehicle, bridge, machinery only but can be used for any structures subjected to dynamic loads and vibration.

(19) Below is the example of the viscoelastic bracing damper (100) for dissipating part of energy of the dynamic load or vibration load, from which the advantages of the present invention may be more readily understood. It is to be understood that the following examples are for illustrative purpose only and should not be construed to limit the present invention in any way.

EXAMPLE

(20) A viscoelastic bracing damper (100) for dissipating part of energy of the dynamic load or vibration load was developed and shown in FIGS. 1-2. Referring to FIGS. 1-2, the viscoelastic bracing damper (100) comprises a cylinder (101) has an inner core (102) transversed therethrough without contacting an inner surface of the cylinder (101), thereby having a barrel portion formed between the inner surface of the cylinder (101) and the inner core (102). A damping means (107) is extended substantially along a length of the barrel portion, herein the damping means (107) is compressed between the inner surface of the cylinder (101) and the inner core (102) for absorbing vibration loads. A front connector (104) and an end connector (106) are attached separately to each end of the inner core (102) for installing the viscoelastic bracing damper (100) to a structure joint.

(21) FIG. 3 shows a viscoelastic bracing damper (100) is installed to a frame structure connected by a front connector (104) and end connector (106).

(22) FIG. 4 shows a steel frame structure and FIG. 5 shows a graph of reaction force with applied displacement for steel bare frame structure in FIG. 4. The steel bare frame as shown in FIG. 4 is without any bracing or damper and therefore high displacement is shown in FIG. 5.

(23) FIG. 6 shows a steel frame with chevron bracing subjected to lateral cyclic load. The steel frame is slightly destroyed as shown in FIG. 6 due to lateral cyclic displacement. FIG. 7 shows the result of displacement with base shear for steel frame in FIG. 6. According to the result in FIG. 6, excessive displacement and unstable base shear are shown. In contrast, a steel frame with viscoelastic bracing damper (100) subjected to lateral cyclic load is shown in FIG. 8. The steel frame with viscoelastic bracing damper (100) in FIG. 8 shows less destruction in comparison with FIG. 6. FIG. 9 shows the result of base shear with displacement for steel frame in FIG. 8. Referring to FIG. 9, the base shear and displacement are showing better performance during cyclic movement in comparison with the result for steel frame with chevron bracing.

(24) Although the present invention has been described with reference to specific embodiments, also shown in the appended figures, it will be apparent for those skilled in the art that many variations and modifications can be done within the scope of the invention as described in the specification and defined in the following claims.

(25) Description of the reference numerals used in the accompanying drawings according to the present invention:

(26) TABLE-US-00001 Reference Numerals Description 100 Viscoelastic bracing clamper 101 Cylinder 102 Inner core 103 Joint 104 Front connector 105 Stopper 106 End connector 107 Damping means