JPH06174632A - Marine real environment tester - Google Patents

Abstract

PURPOSE:To provide a tester capable of measuring a fatigue crack propagation speed and corrosion fatigue strength under a constant wave by adding constant cyclic tensile load caused by the wave to a test piece under a real environment on the sea without receiving influence of change of a sea level in a sea real environment tester. CONSTITUTION:A main float 2 which is guided with a guide column, is vertically movable and floats on the sea surface 25, a plurality of arm members 3 freely fluctuantly connected to the main float 2 with pins and a test piece 5 existing between an end part of each arm member 3 and the main float 2 are equipped. Furthermore, a first float body attached to the other end part of each arm member 3 through a load detection means 4 and working load caused by approximately constant buoyancy on the load detection means 4, and a second float body 8 whose part is exposed on the sea water surface 25 and working fluctuation load on the load detection means 4 are equipped. Accordingly a test result comparable with the test result in a laboratory is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actual marine environment test apparatus.

[0002]

2. Description of the Related Art Conventionally, a seawater environment was simulated as a test device for measuring the fatigue crack growth rate and corrosion fatigue strength affected by waves assuming a severe environment of use under seawater environment. Although there is something to be installed in the room, there is no test device that can perform similar measurements in the actual environment in the ocean so as to be comparable with the test results in this laboratory.

This is because it is difficult to apply a constant repetitive tensile load due to waves to the test piece under the actual environment in the ocean. In other words, there is a change in tide level in the ocean, and the tensile load due to waves on the test piece changes with this change in tide level, which complicates the stress conditions in the actual ocean environment test equipment, and It becomes virtually impossible to compare with the test results of. Moreover, the tide level changes depending on the place and time.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional technical problems, and the structure thereof is a guide column which is erected perpendicularly to the sea surface and the guide column. And a main float floating on the surface of seawater, and a plurality of pins that are swingably pin-coupled to the main float. An arm member, a test piece that is interposed so that a tensile load acts between one end of each arm member and the main float, and is located below the sea level, and a load detecting means is provided at the other end of each arm member. Is attached below the surface of the seawater and is connected to the upper side of each of the first uki body by which a load due to a substantially constant buoyancy is applied to the load detecting means, and in a normal state,
It is a marine real environment testing device, characterized in that a part of it is provided with a second body that is exposed on the surface of seawater.

[0005]

According to this marine environment tester, the load detecting means is constantly subjected to a substantially constant tensile force due to the buoyancy of the first floater when the test piece is placed in the corrosive environment of seawater. As the sea level changes up and down due to waves,
A fluctuating tensile force is added by the fluctuating buoyancy of the second flat body.
In this way, the pulling force acting on the load detecting means with a slight variation acts on the test piece via the arm member.
Since the arm member is swingably connected to the main float at the intermediate portion by a pin, the load acting on the test piece is
The tensile force acting on the load detecting means may be increased according to the leverage of the arm member.

With respect to general waves, a large main float to which a plurality of arm members are attached gives only a slight vertical fluctuation, which causes a reliable change in buoyancy in the second float body. Based on this, the tensile force acting on the other end of the arm member becomes a fluctuating load and reliably acts on the test piece.

The change in the load acting on the test piece based on the change in the tide is caused by the main float sliding along the guide column.
Be absorbed. That is, the main float, the test piece, the arm member, the load detecting means, the first buccal body, the second buccal body, etc. are kept in a predetermined positional relationship and are moved up and down as the sea level changes due to the change in tide level. It moves and the change in tide level is absorbed.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show an embodiment of an actual marine environment test apparatus according to the present invention. In the figure, reference numeral 1 indicates a guide strut, and the guide strut 1 is a state in which a plurality of (two in this embodiment) are vertically arranged with a predetermined distance from the quay 13 on the sea side, and are mounted on the quay 13. It stands upright at a right angle to the sea surface 25.

Specifically, the plurality of guide columns 1 are connected at their upper and lower ends by parallel connecting members 11a and 11b, and are arranged in parallel with the respective guide columns 1 on the quay 13 side. The lower ends of the vertical members 12 facing each other and the guide columns 1
And the lower end portions of the parallel horizontal members 18 are connected to each other. In addition, the upper ends of the vertical members 12 are connected to each other by the connecting member 11
It is connected by an upper transverse member 19 parallel to a and 11b. Further, both ends of the connecting member 11a located at the upper end of each guide column 1 and the central portion of the upper lateral member 19 are connected by a pair of inclined upper members 20. And, the quay 1 by the pair of mounting members 21 coupled to the upper lateral member 19.
In addition to being fixed to 3, the contact member 22 provided in the intermediate portion of each vertical member 12 is in contact with and supported by the quay wall 13.

In this way, with the plurality of guide pillars 1 mounted on the quay 13, the guide pillars 1 are erected perpendicularly to the sea surface 25, regardless of changes in tide level due to differences in place or time. It is installed so that the sea surface 25 is always present in the middle of the guide column 1. Reference numerals 31 and 32 are work passages, respectively, and the floor surface is formed of a net, expanded metal or the like.

A main float 2 is slidably supported in the vertical direction on the guide column 1, and the main float 2 floating on the sea surface 25 is guided by the guide column 1 and is vertically movable. Actually, the main float 2 is configured by horizontally connecting a plurality of (six in this embodiment) float bodies 2a as shown in FIG. The two guide columns 1 are inserted to prevent the main float 2 from rotating around the axis of the guide column 1 and vertically swinging both ends in the lateral direction.

The main float 2 has a supporting member 14, an arm member 3, a load detecting means 4 and a test piece 5 which will be described later.
A weight adjusting mechanism (not shown) is provided so that the buoyancy of the first and second buccal bodies 7 and 8 is applied so that the buoyancy is floated on the sea surface 25. If the guide strut 1 is given an irregular cross section other than a circular shape, and the guide strut 1 is non-rotatably inserted through the main float 2 having a through hole adapted to this, one guide strut 1 It is possible to guide the main float 2.

A plurality of support members 14 (five on each side of the main float 2 in this embodiment) are fixed to the main float 2. Each support member 14 hangs from the main float 2, and a pair of upper and lower brackets 14a and 14b are fixed to the lower end portion thereof as shown in FIG. An intermediate portion of the arm member 3 is swingably coupled to and supported by the lower bracket 14b by a pin 26.
A test piece 5 is interposed between 4a and one end of the arm member 3. That is, one end of the test piece 5 has the pin 1
6 is swingably coupled to the upper bracket 14a, and the other end is swingably coupled to one end of the arm member 3 by a pin 17. This test piece 5 is a compact tension test piece, and a notch is provided when measuring the fatigue crack growth rate. Reference numeral 30 denotes a stopper attached to the lower bracket 14b, which restricts excessive swinging of the arm member 3 when the test piece 5 is broken.

Then, the first support member 7 is attached to the other end of the arm member 3 via the load detecting means 4. First body 7
Is supported on the other end of the load detecting means 4 whose one end is fixed to the arm member 3 via a connecting tool 28, and is always supported on the sea surface 2
The load detecting means 4 is located at the lower part of the table 5, and a relatively large and relatively large tensile force due to buoyancy is constantly applied to the load detecting means 4. Since the first float body 7 is supported away from the main float 2 via the arm member 3 in this manner, the first float body 7 is prevented from interfering with the main float 2 or the guide column 1, and the lever is also used. According to the principle, the buoyancy of the first flat body 7 is expanded, and the test piece 5 can be loaded with an appropriate amount of tensile force. Each load detecting means 4 is, for example, a beam type load cell made of stainless steel, and can be covered with a rubber cover to prevent corrosion. Each load detecting means 4 is connected to a recorder (not shown) mounted on the quay 13 by wiring so that each detected load can be read.

Further, a second balk body 8 is connected to the first broom body 7 via a connecting member 18. The second body 8 is located above the first body 7 under the influence of buoyancy, and a part of it is on the sea surface 25.
Normally exposed on top. Then, the second floating body 8 which receives the buoyancy receives a fluctuating load based on a relatively small buoyancy, which floats up and down due to the vertical movement of the sea surface 25 caused by the wave including the tidal current, through the first floating body 7. To act on the load detecting means 4. The stress ratio R (minimum stress / maximum stress) acting on the load detecting means 4 is adjusted for each load detecting means 4 by adjusting the size, that is, the buoyancy of the first or second duck body 7 or 8 as described above. Can be changed arbitrarily. 29
Is a plate member horizontally fixed to the lower end portion of the support member 14, and the plate member 29 has a function of suppressing the main float 2 from moving up and down under the influence of waves.

Next, the operation of the above embodiment will be described.
When the marine real environment test device having the above structure is operated, the load detection means 4 has a substantially constant and relatively large buoyancy force due to the buoyancy of the first float body 7 in a state where the test piece 5 is immersed in seawater which is a corrosive environment. The tensile force always acts, and as the seawater level 25 changes vertically due to waves, a relatively small fluctuating tensile force due to the fluctuating buoyancy of the second floater 8 is added. In this way, the tensile force acting on the load detecting means 4 accompanied by a slight change acts on the test piece 5 interposed between the upper bracket 14a and one end of the arm member 3.

One end of the test piece 5 is swingably connected to the upper bracket 14a by a pin 16 and the other end thereof is swingable to one end of the arm member 3 by a pin 17. The arm member 3 is swingably connected to the lower bracket 14b by a pin 26 at an intermediate portion thereof, and the upper and lower brackets 14a and 14b are respectively connected via the support member 14 to the main float. Since it is attached to the test piece 5, the load acting on the test piece 5 is the load detecting means 4
The load acting on is expanded according to the leverage ratio.

Waves of a normal size give a slight vertical fluctuation to the horizontally long main float 2 and cause a reliable change in buoyancy in the second flat body 8, so that the buoyancy of the arm member 3 is used. The fluctuating tensile force that acts on the other end acts as a fluctuating load on the test piece 5 and reliably acts.

The change in the tensile force acting on the load detecting means 4 or the tensile load acting on the test piece 5 based on the change in the tide level is absorbed by the main float 2 sliding along the guide column 1. That is, the main float 2, the supporting member 14, the test piece 5, the arm member 3, the load detecting means 4, the first flat body 7,
While maintaining the positional relationship shown in FIG. 1, the second flat body 8 and the like move up and down with the change in the sea level 25 based on the change in the tide level, and the buoyancy of the second flat body 8 due to the change in the tide level. Is prevented from increasing or decreasing. In this way, each test piece 5
It is possible to measure not only the fatigue crack growth rate but also the corrosion fatigue strength. In addition, it is also possible to perform a bending test and a tensile test in a corrosive environment due to seawater by using this actual ocean environment test device.

[0020]

As can be understood from the above description,
According to the marine actual environment test device of the present invention, it is possible to apply a substantially constant repeated tensile load due to waves to the test piece under the actual environment in the ocean without being affected by the change in tide level, Provided is a test device for measuring a fatigue crack growth rate, a corrosion fatigue strength, etc. under substantially constant waves. As a result, according to this ocean real environment test device,
It is possible to obtain test results that can be compared with the test results in the laboratory.

[Brief description of drawings]

FIG. 1 is a front view showing an actual marine environment test apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view of the same.

FIG. 3 is an enlarged front view of the mounting portion of the test piece.

[Explanation of symbols]

1: Guide post, 2: Main float, 3: Arm member, 4:
Load detection means, 5: test piece, 7: first flat body, 8: second
Flat body, 13: Quay, 14: Support member, 16, 17, 2
6: Pin, 18, 28: Connecting tool, 25: Sea surface.

Claims (1)

[Claims] 1. A guide column standing upright at right angles to the sea surface, and vertically movable by being guided by the guide column, and
A main float that is not rotatable about the central axis of the guide column and floats on the sea surface, a plurality of arm members that are swingably pin-coupled to the main float, one end of each arm member, and A test piece that is placed so that a tensile load acts between it and the main float, and that is located below the seawater level and attached to the other end of each arm member via load detection means. A first skive body which applies a substantially constant buoyancy load to the load detecting means, and a second skive body which is connected above each first skive body and is partially exposed above the sea surface in a normal state. An actual marine environment test device comprising: