JPS58218562A - Wind resistant and vibration-proof apparatus of rectangular structure - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wind and vibration resistant device for angular structures such as bridges, buildings, towers and tanks, and chimneys.

In the inverted trapezoidal box girder bridge (1), as shown in Figure 1,
The flow separates from the corner of the bridge and a Karman vortex (2) is generated in the wake, and a vortex vibration force acts on the bridge (1), causing the bridge (1) to vibrate.

In order to suppress this vibration, installing flaps (3), fairings (4), and cowlings (5) as shown in Figure 2 will suppress flow separation at the corners and exert a vibration-proofing effect. Ru. Depending on the cross-sectional shape, the fluff (3)
Alternatively, a combination of double flaps (3') as shown in FIG. 6 may be used.

However, it is difficult to completely suppress vibration using the allocation device shown in FIGS. 2 and 3. Especially the fairing (4) is f! Depending on the cross-sectional shape of the beam, vibration may be adversely affected.

The present invention has been proposed in order to eliminate these drawbacks, and includes a spoiler that dams and disturbs the flow by disposing a spoiler outside the corner of a square structure with a gap between the corner and the structure. The present invention relates to a windproof and vibration isolating device for a square structure.

As mentioned above, in conventional angular structures, flaps,
Fairings and cowlings were used to rectify the flow and suppress vibrations.

In the present invention, a spoiler disposed outside the angular structure with a gap from the structure actively disturbs the flow, and the spoiler is used to actively disturb the flow of the angular structure. 2. Damping the vortices generated when the flow separates from the
The present invention suppresses the generation of Karman vortices and increases the effect of canceling the excitation force. According to the present invention, the construction and installation of the vibration isolator is easier than with conventional devices.

The present invention has many advantages, such as being able to provide excellent vibration damping effects.

The present invention will be described below with reference to the illustrated embodiments.

In Fig. 4, (11) is an inverted trapezoidal box girder cross beam, and there is a conventional flap (1
2) is attached, and a spoiler (13) made of a plate-shaped body that has a gap and extends outward and diagonally downward is attached to the outside of the lower corner of the overhang.

Therefore, the flap (12), which is a conventional vibration isolator, is used for bridges (
11) Prevent the flow from separating from the upper corner (α).

The spoiler (13) traps the vortices generated when the flow separates from the corner (b) of the lower surface of the bridge (11) in the lower part of the overhang as shown in (C), and also as shown in (j). By actively disturbing the flow, the generation of Karman vortices is suppressed and the assisting force is eliminated.

Figure 5 shows the experimental setup for this vibration isolator, which is a cross-sectional model of an inverted trapezoidal box girder bridge (pl is supported by springs (ql) at the top and bottom, and the wind is blown from the side at an angle of attack θ as shown by the arrow (r). We conducted a wind tunnel experiment.

Figures 6(a) to (di indicate the specimens, Figure 6(al)
is a basic inverted ladder cross-section bridge cross-sectional model without vibration isolators (
7)), Fig. 6h shows a model in which a flap (3), which is a conventional vibration isolator, is attached to the model (7)) in a basic cross section, and Fig. 6C shows a model in which a flap (3), which is a conventional vibration isolator, is attached to the model (7) in a basic cross section. Figure 6d shows a model with the flap (3) and the spoiler (13) of the invention attached to the basic cross-sectional model, and Figure 5 shows the four types of models. The graph shown in Fig. 7 is the result of an experiment conducted using the experimental apparatus shown in Fig. 7, and the vibration response due to the wind speed and Karman vortex was measured. Note that this is a comparison of bending vibrations at an angle of attack θ=±7°.

In addition, 0 is a basic cross-sectional model as shown in Figure 66, 2 is a basic cross-sectional model with a flap attached as shown in Figure 6, and K3 is a basic cross-sectional model as shown in Figure 6C. This figure shows a cross-sectional model equipped with the suboice of the present invention. Note that no vibration occurred in the model with the basic cross-sectional shape to which the flap and the spoiler of the present invention were attached.

As a result of the above-mentioned wind tunnel experiment, the vibration amplitude of the bridge model equipped with flaps, which is a conventional vibration isolating device, was only about % lower than that of the basic cross-sectional bridge model without anti-vibration measures, but the present invention It was found that the vibration amplitude of the bridge model equipped with the spoiler of the present invention was reduced to about 100% compared to the bridge model of the basic cross-sectional shape, and that vibrations were completely stopped in the bridge model equipped with the flaps and the spoiler of the present invention. .

8 and 9 respectively show other experimental examples of the present invention. In FIG. 8, the spoiler (13) is formed into a curved surface convexly curved outward, and in FIG. 9, the spoiler (13) )
is formed into a dogleg-shaped cross section that is convexly bent outward.

FIG. 10 shows an embodiment in which the present invention is applied to a building (14), in which a spoiler (13) is provided with a gap between the building (14) and the outside of each corner of the building (14).
) is arranged, and the Karman vortex that occurs in the conventional building (14) is generated as shown in Fig. 11.

This is prevented by the spoiler (13).

Furthermore, FIG. 12 shows an embodiment in which a spoiler (13) is provided on a structure having a circular cross section, such as a chimney (15).

Although the present invention has been described above with reference to embodiments, the present invention is of course not limited to such embodiments, and may be modified in various ways without departing from the spirit of the present invention. It is.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a conventional inverted trapezoidal box girder cross beam, Fig. 2 is a sectional view of the same bridge equipped with an allocation device, and Fig. 3 is a partial vertical sectional view showing another embodiment of the vibration damping device. FIG. 4 is a longitudinal cross-sectional view showing an embodiment of the wind-proof and anti-vibration device according to the present invention, and FIG. 5 is a longitudinal cross-sectional view of the wind tunnel experiment apparatus. Figures 6α, 6h, 6c, and 6d are longitudinal cross-sectional views of the specimens in the wind tunnel experiment, Figure 7 is a graph showing the results of the wind tunnel experiment, and Figures 8 and 9 are other implementations of the apparatus of the present invention, respectively. FIG. 10 is a plan view showing the case where the present invention is applied to a building; FIG. 11 is a plan view showing the state in which Karman vortices are generated in a building; FIG. 12 is a plan view showing the case where the present invention is applied to a chimney, etc. FIG. 2 is a plan view showing a case where the present invention is applied to a structure having a circular cross section. (11)...Bridge, (13)...Spoiler,
(14)...Building, (15)...Chimney. Sub-Agent Patent Attorney Shige Okamoto 2 people outside the kiln 7j Figure 3 24 Figure 5El 8 leaps 10 Figure 1 δ Figure 1j Procedural amendment October 21, 1980 Commissioner of the Patent Office Kazuo Wakasugi 1, Display of the case Patent Application No. 99342 of 1982 2, Title of the invention Windproof vibration isolation device for square structures 3, Person making the amendment Relationship to the case Patent applicant name (62 Mitsubishi Heavy Industries, Ltd. 4, Sub-Agent (6208) 2 others 5, amended order dated 11 Showa (issued in 2008) month, day 6, subject to amendment
Specification, Drawing 7, Contents of Amendment Change "Angle of attack O = ±7°" to "Angle of attack θ = +7" on page 4, line 13 of the specification.
°” and correct it. Figure 4 of the drawings will be corrected as shown in the attached sheet. ↑

Claims (1)

[Claims] 1. A wind and vibration isolator for a square structure, characterized in that a spoiler is disposed outside a corner of the square structure with a gap between the structure and the spoiler for blocking and disturbing the flow.