JPH1062326A - Loading method in bending test - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a loading method in bending test capable of loading an uniformly distributed load with a simple operation. SOLUTION: A sheet 4 is placed on a sample 2 both lower surface ends of which are fixed or freely supported through a sealant 3, and the pressure in the clearance between the sample 2 and the sheet 4 is reduced to closely fit the sample 2 to the sheet 4, whereby a uniformly distributed load is loaded on the sample. Otherwise, a sheet is placed on a sample both lower surface ends of which are fixed or freely supported through a sealant, and a hydraulic pressure is added onto the sample to closely fit the sample to the sheet, whereby a uniformly distributed load is loaded on the sample.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a loading method in a bending test. More specifically, the present invention relates to a loading method in a bending test capable of loading a uniform evenly distributed load.

[0002]

2. Description of the Related Art Conventionally, in a bending test of a structural part, when it is necessary to make a load of a bending load a uniform distribution load, a method of mounting a sand bag is generally employed.

[0003] However, in the method of mounting the sand bags, not only is it difficult to carry out a uniform evenly distributed load, but also the loading of the sand bags is complicated and sometimes involves danger. There is a disadvantage that.

Therefore, as a method of applying a uniform evenly distributed load, a first group of pulleys is hung at equal intervals on a structural member to be tested, and a second group of pulleys is laid on a pulley beam laid in parallel under the group.
A method is proposed in which a pulley group is fixed, a wire is laid between the first pulley group and the second pulley group, and a load is applied to the pulley beam (Japanese Patent Publication No. 51-25754). .

[0005] However, the method of applying a load to the pulley beam not only makes it difficult to load uniformly evenly distributed loads, but also requires many pulleys, and attaches the pulleys to a structural member. There is a disadvantage in that a complicated operation such as a required operation is required.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned prior art, and has as its object to provide a loading method in a bending test capable of loading a uniform evenly distributed load with a simple operation. I do.

[0007]

According to the present invention, a sheet-like material is placed via a sealing material on a sample having both lower ends fixed or freely supported, and the gap between the sample and the sheet-like material is reduced in pressure. A loading method in a bending test (hereinafter, referred to as a first invention) characterized in that an evenly distributed load is loaded on the sample by bringing the sample and the sheet into close contact with each other, and both ends of the lower surface are fixed or Placing a sheet-like material on a freely supported sample via a sealing material, applying a water pressure on the sample, and bringing the sample and the sheet-like material into close contact with each other, thereby loading an evenly distributed load on the sample. And a loading method in a bending test (hereinafter, referred to as a second invention).

[0008]

According to the first aspect of the present invention, a sheet-like material is placed via a seal material on a sample having both lower ends fixed or freely supported, and a gap between the sample and the sheet-like material is formed. By reducing the pressure and bringing the sample and the sheet into close contact with each other, an evenly distributed load can be uniformly applied to the sample.

According to the second aspect of the present invention, a sheet-like material is placed via a sealant on a sample having both lower ends fixed or freely supported, and a water pressure is applied on the sample, whereby the sample and the sheet By bringing the sample into close contact with the sample, an evenly distributed load can be uniformly applied to the sample.

[0010] In the second invention, the gap between the sample and the sheet may be depressurized at the same time as applying water pressure to the sample.

Hereinafter, the first and second inventions will be described with reference to the drawings.

FIG. 1 is a schematic explanatory view of a loading method in a bending test according to the first invention.

In FIG. 1, reference numerals 1a and 1b denote supports, and a sample 2 is placed on the supports 1a and 1b. The sample 2 includes, for example, a veneer such as a plywood and a structural member such as an FRP sandwich panel.

On the sample 2, a sealing material 3 is placed. The sealing material 3 is made of, for example, a synthetic resin such as butyl rubber or fluorine resin, and has a diameter of 10 to 100 mm.
Examples of the sealing material include a cord having a length of about 30 to 100 mm and a cross section having a height of about 5 to 30 mm having a rectangular cross section. The sealing material 3 is arranged such that a gap 5 formed between the sheet 2 placed on the sealing material 3 and the sample 2 is shielded from an external space. Since the bending test of the sample 2 is performed between the support 1a and the support 1b, the position where the seal material 3 is provided is at least the end of the sample 2 more than the support 1a and 1b as shown in FIG. It is desirable to be on the side close to the part. As described above, when the sealing member 3 is provided, the uniformly distributed load can be uniformly applied to the sample 2 provided between the support 1a and the support 1b.

Examples of the sheet material 4 include a rubber sheet made of rubber such as butadiene rubber, butyl rubber, chloroprene rubber, styrene butadiene rubber, isoprene rubber, and nitrile rubber, and a resin sheet made of resin such as soft vinyl chloride resin and polyethylene. Non-permeable sheet. The thickness of the sheet-like material 4 is not particularly limited, but usually may be about 1 to 5 mm in consideration of mechanical strength and adhesion to the sample 2.

Next, the pressure in the gap 5 is reduced, and the sample 2 and the sheet 4 are brought into close contact with each other. As described above, when the sample 2 and the sheet material 4 are brought into close contact with each other, an atmospheric pressure is applied to the sample 2 via the sheet material 4, and this atmospheric pressure becomes a load. When using such atmospheric pressure, sample 2
Atmospheric pressure is uniformly applied as a uniformly distributed load.

Therefore, according to the method of the first invention, it is possible to uniformly load the sample 2 with the atmospheric pressure as a uniform distribution load.

The method of the first invention does not require a sand bag or a group of pulleys as in the prior art. Basically, the sheet-like material 4 is placed on the sample 2 and depressurized. Since it is good, a uniformly distributed load can be easily and uniformly applied on the sample 2.

FIG. 2 is a schematic explanatory view of a loading method in the bending test according to the second invention.

In FIG. 2, the types and materials of the supports 1a and 1b, the sample 2, the sealing material 3, and the sheet 4
The positional relationship between them may be the same as in the embodiment shown in FIG.

In the second invention, a water pressure is applied on the sample 2 to bring the sample 2 and the sheet-like material 4 into close contact with each other.
Since a method of applying an evenly distributed load to the sample 2 is adopted, a water pressure application frame 6 is placed on the sheet 4 as shown in FIG. At this time, it is preferable to sufficiently seal the boundary between the water pressure applying frame 6 and the sheet-shaped material 4 with, for example, a silicon-based elastic sealing material in order to prevent water from leaking.

Examples of the water pressure application frame 6 include molds made of various metals, rubbers, plastics and the like.

The size of the water pressure imparting frame 6 is determined because the bending test of the sample 2 is performed between the support 1a and the support 1b.
As shown in FIG. 2, it is desirable that the water pressure application frame 6 be placed at least at a portion closer to the end of the sample 2 than the supports 1 a and 1 b.

By injecting the water 7 into the water pressure application frame 6, a uniform and uniformly distributed load can be applied to the sample 2. At this time, by adjusting the water column of the water 7 injected into the water pressure imparting frame 6, the uniform distribution load applied to the sample 2 can be easily adjusted.

Further, the plate is placed on the water 7 in the water pressure applying frame 6 so as not to have a gap with the water pressure applying frame 6, and pressure is applied on the plate or By providing a space between the body and the water 7 and blowing the pressurized air into the space, the water in the water pressure application frame 6 is pressurized,
It is possible to generate a larger evenly distributed load.

It should be noted that in the second invention, the first
Similarly to the invention, the pressure between the sample 2 and the sheet 4 is reduced by reducing the pressure between the sample 2 and the sheet 4,
A uniform and uniformly distributed load can be applied to the sample 2 using the atmospheric pressure.

In the method of the second invention, the sheet-like material 4 is basically placed on the sample 2 without the necessity of a conventional sand bag or a group of pulleys. The uniform distribution load can be evenly applied to the sample 2 simply by placing it and injecting the water 7 into the water pressure application frame 6, so that there is an advantage that the operation is simple. Further, the second invention has an advantage that the uniform distribution load applied to the sample 2 can be easily adjusted only by adjusting the height of the water column of the water 7 injected into the water pressure application frame 6. is there.

[0028]

Next, the loading method in the bending test of the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 A loading method having an embodiment as shown in FIG. 1 was employed.

That is, the supports 1a and 1b have a diameter of 5 mm.
Using a 0 mm steel tube, the support 1a and the support 1b were disposed so as to be in a parallel state, and the interval between them was set to 2000 mm.

As sample 2 on supports 1a and 1b, 24
A FRP sandwich panel of 00 × 1200 × 50 mm was placed, and a frame-shaped sealing material 3 (material: butyl rubber, sectional shape: 50 × 2) was placed at a position 100 mm from the end of the sample 2.
0 mm), and a 3000 × 1800 × 3 mm butyl rubber sheet as the sheet material 4 was placed on the sealing material 3.

Next, the pressure between the sample 2 and the sheet 4 was reduced by using a vacuum pump to bring the sample 2 and the sheet 4 into close contact with each other.
It was confirmed by the vacuum pressure gauge installed in the gap between the sample 2 and the sheet 4 that mHg was loaded.

Example 2 In the same manner as in Example 1, the sample 2 was placed on the supports 1a and 1b.
The sealing material 3 and the sheet material 4 were sequentially placed.

Next, a water pressure applying frame 6 is placed on the sheet 4.
A plywood formwork of 500 × 12 mm was placed, and the contact portion between the sheet-like material 4 and the water pressure application frame 6 was sealed with joints.

A water column having a water column of 400 mm
Then, it was confirmed by a strain gauge that the sample 2 was evenly loaded with a water column having a uniform distribution load of 400 mm.

From the above, it can be seen that according to the loading method in the bending tests of Examples 1 and 2, a uniformly distributed load can be loaded on the sample 2 uniformly.

[0037]

According to the loading method in the bending test of the present invention, it is possible to load a uniform and uniformly distributed load with a simple operation.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of a loading method in a bending test according to the present invention.

FIG. 2 is a schematic explanatory view of a loading method in a bending test according to the present invention.

[Explanation of symbols]

 2 sample 3 sealing material 4 sheet

Claims (3)

[Claims] 1. A sheet-like material is placed via a sealing material on a sample having both lower ends fixed or freely supported, and the gap between the sample and the sheet-like material is reduced in pressure. A loading method in a bending test, wherein an evenly distributed load is loaded on a sample by bringing the sample into close contact with an object. 2. A sheet-like material is placed via a sealing material on a sample whose both ends are fixed or freely supported on a lower surface, and a water pressure is applied on the sample to bring the sample and the sheet-like material into close contact with each other. A loading method in a bending test, wherein a uniformly distributed load is loaded on the sample. 3. The loading method in a bending test according to claim 2, wherein a water pressure is applied on the sample and a gap between the sample and the sheet is reduced.