JPS6137316A - Composite damping steel plate - Google Patents

Abstract

PURPOSE:To provide the titled composite damping plate to which a damping is given by a proper face contact of both steel plates by fixing with welding two pieces of steel plates each other at plural places or by fixing with welding through the hole by interposing a clip plate according to the circumstances. CONSTITUTION:Two pieces of steel plates are fixed with welding each other at scattering plural places. An clip plate is intervened, if necessary, on the welding place and the fixing with welding is made through the hole. In case of the face contact of both steel plates being solid or a space being interposed quitely between the damping effect due to friction is eliminated, but in case of a proper light face contact being made the damping is given. Consequently the damping is held and the cost can be reduced without the medium of a damping alloy and high molecular resin, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a composite steel plate with good vibration damping properties, in which two steel plates are stacked one on top of the other and vibrations are absorbed by the frictional action of their mutual contact surfaces.

(Prior Art) Noise and vibrations occur in civil engineering construction machines, ships, etc., which occur along the S axis of the human body. For this reason, several damping materials have been developed.

As a vibration-proof alloy, magnesium, Cu-Mn alloy, flake graphite cast iron, Fe-cr-At alloy, 12%Crg4
There is. However, although these anti-vibration alloys exhibit good performance under no-load conditions, when they are incorporated into structures as strength members, their anti-vibration effects disappear due to static loads or residual stress from welding. Often. Furthermore, vibration damping alloys have the disadvantage that they are expensive and difficult to weld.8 Composite vibration damping steel plates are composite plates made by combining a viscoelastic polymer resin and a steel plate. It has an effect when incorporated into structures, and is used in automobile parts, etc. However, the welding process is very time consuming, and the strength of the material in terms of cross-sectional area deteriorates. Furthermore, since polymer resins deteriorate over time, they cannot be used in structures with harsh operating environments, such as ship decks or one-point flues.

(Problems to be Solved by the Invention) The object of the present invention is to obtain a vibration-damping steel plate that is inexpensive and can be transported, processed, and welded as a general industrial member without becoming obsolete over time.

(Means for solving problems) The present invention eliminates the drawbacks of the above vibration damping materials.

Although it is a composite type, unlike the composite plate mentioned above, it does not use viscoelastic resin and can exert a vibration damping effect through contact friction between the surfaces of the steel plates, which eliminates the drawbacks of conventional composite vibration damping steel plates. .

The present invention is a composite vibration-damping steel plate made by superimposing two steel plates, and the two steel plates are welded and fixed to each other at a plurality of locations, or if necessary, there is a The gist is that the washer is inserted so that the welded fixation part passes through the hole in the washer.

As a result of experiments, the present inventor found that by stacking two steel plates as a composite vibration damping steel plate, it is possible to impart vibration damping properties through contact between the surfaces of the steel plates.

In other words, to overlap two steel plates, a bar or pipe passed through the plates is fully welded at both ends, and the plates are welded into holes drilled in the plate, or the plates are spot welded together. We found that it is important not to increase the contact surface pressure between the two plates in order to increase the vibration damping effect.If the contact surface pressure is large, the surfaces will not shift from each other, so vibration damping due to shear friction will occur. No expected effect.

On the other hand, if there is no contact at all and a gap is created between the plates, there will be no shear friction and, as a result, the damping effect will be lost.

The reason why the damping effect is produced when the contact surface pressure is not increased is as follows. That is, since the contact surface pressure on the plate surface is small, no restraint is exerted on the tangential direction of the plate surface, so that deviation occurs. At this time, the energy of the shear friction, which is the product of the displacement of the shear and the frictional force, is absorbed, resulting in a vibration damping effect. The vibration damping effect due to the shear friction of the transverse waves is the greatest. The longitudinal waves are also superimposed on the transverse waves. At the interface of a plate, in the case of a transverse wave, one side of the interface is in a tensile stress state and the other side is in a compressive stress state, whereas in the case of a longitudinal wave, a phase difference occurs on both sides of the interface during propagation, resulting in sparse parts. A portion occurs where the dense portion and the thin portion make contact with each other at the interface, where the sparse portion generates a tensile stress component and the dense portion generates a compressive component of stress, which cancel each other out through shear friction at the interface. This phenomenon produces a longitudinal wave damping effect.

The shape of the welded portion of the plate and the density of the welded portion relative to the plate area may be such that the contact surface pressure between the two plates is small and the contact surface is shifted so as to occur in the following shape and ratio.

Examples of welded fixation structures are shown in Figures 1 (a), (b), and (c). In both cases, the plates (1) and (1') are in contact with each other around the welded area. (b) is a bar (
Both ends of 2) are joined by a plate and a welded part (3),
(B) shows a hole drilled in a plate that is filled with welding (4), and (C) shows a plate that is spot welded (5) together.

In the case of such a welded fixed part structure, the contact surface pressure is high near the welded fixed part, but the contact surface pressure decreases toward the middle between the welded fixed part and the adjacent 18 welded fixed part. Therefore, in order to increase the damping performance to δ, a washer (6
) It has been found that it is effective to insert the welded part so that it passes through the hole in the washer. Their structures are shown in Figure 2 (a), (b), and (c). (a) is bar (2)
The two ends of the plate are joined to the welded part (3), and the washer (6) is completely inserted between the two plates. (c) has a washer (6) inserted between the plates, and (c) has a washer (6) inserted between the plates with spot welding (5) between the plates. show something

By inserting a washer between the plates, compared to the case without the washer, the surface pressure near the welding point is the same thickness, but it is different from the welding point. It was possible to further reduce the contact surface pressure at the intermediate point with the welded fixation point, thereby further improving vibration damping performance.

The plate can be made structurally strong by providing multiple welding points. If these welding points are made slightly denser, 1
It becomes the same as a single board and loses its damping properties.
- + r 觔子 L 采田 11 鯵 か くし し た だ し た だ が Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ Ｇ cus

From the viewpoint of vibration damping, it was appropriate that the density of the welded parts be less than D20 per 1 m'. At this time, although it depends on the mutual friction coefficient between the plate surfaces, the appropriate contact surface pressure required to generate shear friction to improve damping performance is 15 to 9 seas or less. It was also desirable to remove the weld beads on the surface of the plate using a grinder.

(Example, action) Next, embodiments of the present invention and their damping effects will be described.

Table 1 shows invention examples N-11 to 4 and comparative example No. 5,
The materials, plate dimensions, welding fixation, and vibration damping effects are shown below.

The arrangement of welding points for Nos. 1 to 4 is shown in Figure 3 (A) (
b) Shown in (c). As shown in the figure, each plate is 500 strands wide x 150 lbs (l long) with welded parts A, C, H...
...Ri was placed. The converted number of welding points is A, 口,
C, 2 (4 places) are at the center VC, S of the side edge of the board, so they are called Chigi, He, To, Chi, and Su (4 places) are at the corners of the board, so they are called Civil Engineering, and H (1 place). Since it is in the center, it can be calculated as one line. (B) The total for the figure is +X4+-)
X4+1=4, which is the area of the board 1.5m x 0.
5m = 0.75mJC distribution, the welding point density is 4 pieces and 70.75m'. (Similar calculation for Figure 1: 3 lines/0.75 m', G' → 2 lines, 70.75 m2,) Figure 3: 70.75 m'
becomes. The vibration damping performance required for all welding locations is 1m2.
Right! Satisfy 120 points or less.

No. 141-5 was struck with a hammer to generate vibration, and its damping effect was confirmed by the peak sound pressure level of the vibration.

Figures 4 (a) (front view) and (b) (side view) show the method for measuring the peak sound pressure level of the board. (b) Figure 4 shows the method of measuring the peak sound pressure level of the board. Figure 5 shows the vibration generated by hitting the plate at a 30° swing-up angle. This is a diagram showing how the pressure level changes over time.The sound pressure peak occurs immediately after the impact, and the highest point (9) is the peak sound pressure level (
the whole from end to end).

The continuous peak sound pressure levels shown in Table 1 are as follows:
It is 94 to 95 dB and 108 t of comparative example NO5.
It was much lower than liE, and the damping effect was remarkable.

(Effects of the Invention) As explained above, the two-sheet Mi composite steel plate of the present invention is easy to transport, process, and weld, and is suitable for use in civil engineering and construction machinery.
It can be used in horizontal parts of ships, etc. to provide a vibration absorbing effect, and its effects are extremely large.

[Brief explanation of the drawing]

Figure 1 (a) is a cross-sectional configuration diagram showing the bar both ends welded and fixed, (b) is embedded welding, and (c) is pot welded.
The figure shows the case where washers are inserted, and (A) shows that the bar is fixed by welding at both ends (
A cross-sectional configuration diagram showing the state of close embedding → spot m contact, Figure 3 (a), (b) (/J) is an example of the present invention
, 2・314 explanatory diagram showing the welding location, Fig. 4 (6) (
[Front view] (B) (side view) is an explanatory diagram showing a method for measuring the peak sound pressure level of the plate, and FIG. 5 is a diagram showing the generation situation of the sound pressure level. ■: Steel plate, 2: Bar, 3: Welded part, 4: Closely embedded, 5: Nupot weld, 6: Washer, 7: Hammer, 8:
Node point, 9: Peak sound pressure level, Figure 1 Figure 3 (A)
(b) 4 pieces 10.75m2 (c)
(d) 2 pieces 10.75m2
3/' (1,75m2 Figure 4 (A) (B) Figure 5 Time

Claims (2)

[Claims] (1) A composite vibration-damping steel plate made by stacking two steel plates, characterized in that the two steel plates are welded and fixed to each other at a plurality of locations. (2) A composite vibration-damping steel plate made by stacking two steel plates, in which the two steel plates are welded and fixed to each other at multiple locations, and between the two steel plates, the welded fixation part is inserted into the washer's hole. A composite vibration damping steel plate characterized by having a washer inserted through it.