JPH0843217A - Instrument for measuring wave load of marine vessel - Google Patents

Abstract

PURPOSE:To stably measure the wave load acting on the side of a marine vessel having a double-shell hull. CONSTITUTION:A laser displacement gauge 10 composed of a laser transmitter 8 and a laser receiver 9 is provided between adjacent transformers 4 which are arranged so that the interval between an outer shell 2 and inner shell 3 can be maintained. The transmitter 8 is positioned to emit laser light 8a toward the central part of the lounge 5 of the outer shell 2 in the length direction from an horizontally oblique direction and the laser receiver 9 is positioned symmetrically to the transmitter to detect the reflected light 8b of the laser light 8a. A controller 11 which calculates the wave load to a marine vessel by finding the deformation of the lounge 5 based on the detecting signal of the receiver 9 and recorder 12 which records the calculated results of the controller 11 are also provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wave load measuring device for ships having a double shell structure.

[0002]

2. Description of the Related Art In a large ship such as a container ship, as shown in FIG.
There is a double shell structure consisting of and.

In the above ship, long-term measurement of the wave load acting on the ship side is an important matter in terms of structural strength. As one of the conventional methods for measuring such wave load,
There is a method using a strain gauge. That is, as shown in FIG. 4, a transformer 4 arranged between the outer shell 2 and the inner shell 3 on the side portion of the ship that constitutes the hull 1 having a double shell structure from the outer shell 2 and the inner shell 3. Longe 5 on the outer shell 2 side located between
The strain gauges 7 are attached to the face material 5a of the
2 pieces are used by sticking them to the center and the center, and the outer shell 2
The stress associated with the bending of the longe 5 when the is deformed is measured by each of the strain gauges 7, and the value is converted into a wave load. Reference numeral 6 denotes a longe of the inner shell 3.

[0004]

However, since the strain gauge 7 is used by pasting it, it may be peeled off after a long period of time and has a problem of durability.
There is also a problem in terms of reliability because the measured value changes subtly due to disturbance such as noise.

Incidentally, there is a method of embedding a pressure gauge by making a hole in the outer shell 2, but such a method is not so preferable because the construction for making a hole in the hull structure must be carried out. The work for sealing the parts must be done accurately, and there is a problem that it takes time to install.

In view of the above, the present invention has a highly reliable wave load that can be easily installed without the need to make holes in the outer shell and can stably measure the wave load for a long period of time. It is intended to provide a measuring device.

[0007]

In order to solve the above-mentioned problems, the present invention provides the above-mentioned outer shell of a hull of double shell structure in which the outer shell and the inner shell reinforced by longes are partitioned by a transformer. A laser displacement meter consisting of a laser light emitter that emits a laser beam and a laser light receiver that detects the reflected light is installed between adjacent transformers in the central part of the longe near the waterline level of the hull of the shell. Then
In addition, the controller is configured to calculate the wave load acting on the outer shell based on the reflected light detected by the laser light receiver, and the recorder for recording the calculated value by the controller.

[0008]

When laser light is emitted from the laser light emitting device toward the longitudinal center of the outer shell, the reflected light is detected by the laser light receiving device and sent to the controller. The controller calculates the amount of deformation of the longe based on the detected displacement of the reflected light from the reference position, calculates the wave load acting on the outer shell, and records it in the recorder.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

1A and 1B show an embodiment of the present invention, in which a transformer 4 is arranged between the outer shell 2 and the inner shell 3 at a required interval in the bow-stern direction, and The outer shell 2 and the inner shell 3 are attached to each other by maintaining a distance between the shell 2 and the inner shell 3 and attaching a number of longes 5 and 6 extending in the bow-stern direction to the inner surface of the outer shell 2 and the outer surface of the inner shell 3, respectively. At the side part of the ship having the hull 1 of the double shell structure which is designed to be reinforced, the hull draft line D. Outer shell 2 located at a level slightly lower than the L level
A laser displacement meter 10 composed of a laser light emitter 8 such as a laser diode and a laser light receiver 9 such as a photodiode is installed at a position between adjacent transformers 4 for the long distance 5 on the side. By calculating the value detected by the controller 11 with the outer shell 2
Be able to measure the wave load acting on.

More specifically, the laser light emitter 8 is provided at one corner portion of the longe 6 on the inner shell 3 side and the transformer 4 in the longitudinal center of the face material 5a constituting the longe 5 on the outer shell 2 side. The laser receiver 8 is installed so as to be capable of irradiating the laser beam 8a obliquely from the horizontal direction, and the laser light receiver 9 is provided at the opposite corner formed by the longe 6 and the transformer 4 on the inner shell 3 side. The laser light emitter 8 is installed symmetrically in the bow-stern direction so that the reflected light 8b of the reflected light 8b from the reference position of the reflected light 8b due to the deformation of the longe 5 detected by the laser light receiver 9 can be received. The controller 11 is configured to calculate the amount of deformation δ of the longe 5 based on the displacement x to calculate the wave load w, and the recorder 12 that records the result calculated by the controller 11.

When the wave load acting on the outer shell 2 is to be measured, the longe 5 attached to the outer shell 2 from the laser emitter 8 of the laser displacement meter 10 in advance in the state where no wave load is acting. The laser light 8a is emitted toward the central portion of the face material 5a in the longitudinal direction, and at this time, the position of the reflected light 8b received by the laser receiver 9 is set as the reference position in the controller 11, and thereafter, the reflected light is reflected. The wave load is measured based on the reference position of 8b.

That is, when a wave load w is applied to the outer shell 2 of the hull 1, the outer shell 2 is deformed inward, and as a result, the longe 5 attached to the inner surface of the outer shell 2 is, for example,
As shown by the chain double-dashed line in FIG. 1B, it will be deformed inward. Therefore, due to this deformation of the longe 5, the reflected light 8b of the laser light 8a radiated horizontally obliquely from the laser light emitter 8 toward the central portion in the longitudinal direction of the face material 5a of the longe 5 is (b) in FIG. At the position deviated from the reference position, as indicated by the chain double-dashed line, the signal is input to the controller 11.

In the controller 11, first, the displacement x of the reflected light 8b that has already been set from the reference position is obtained, and based on this displacement x, the deformation amount δ of the deformed longe 5 is given by δ = x · a / {A ² + (l / 2) ² } ^1/2 (where a is the dimension between the longes 5 and 6, l is the transformer 4,
4), and then from this deformation amount δ, the wave load w is calculated as follows: w = δ · CEI / l ⁴ (C: coefficient (= 384), E: Young's modulus, I: cross section 2 The second moment) is calculated, and the calculated value is recorded in the recording device 12 continuously or at fixed time intervals (for example, every one second). Thereby, the wave load acting on the outer shell 2 can be monitored for a long time.

In the above, the displacement x is caused by the displacement of the irradiation point (reflection point) of the laser beam 8a due to the deformation of the longe 5 caused by the deformation of the outer shell 2. However, the outer shell 2 and the longe 5 are structured. Since the amount of deformation in strength is stable, the displacement x also has a stable value. Further, the deformation amount δ of the longe 5 is a macro value in terms of structural strength as compared with the strain value and is less susceptible to the influence of disturbance, so that the reliability can be improved.

The present invention is not limited to the above-mentioned embodiment, and the laser displacement meter 10 is installed at a laser emitting device 8 and a laser receiving device 9 facing each other as shown in FIG. 2, for example. Needless to say, the transformer 4 may be attached to the transformer 4, and various changes may be made without departing from the scope of the invention.

[0017]

As described above, according to the wave load measuring device for a ship of the present invention, the deformation of the outer shell due to the wave load is prevented by using the laser displacement meter including the laser light emitter and the laser light receiver. It is detected as deformation, and the wave load can be calculated by the controller based on the detected value and recorded by the recorder, so there is no hole in the outer shell and no influence of disturbance. It has an excellent effect that the wave load can be accurately obtained, stable measurement can be performed over a long period of time, and high reliability can be obtained.

[Brief description of drawings]

FIG. 1 shows an embodiment of a wave load measuring device for a ship according to the present invention, in which (a) is a front view and (b) is a plan view.

FIG. 2 is a plan view showing another embodiment of the present invention.

FIG. 3 is a schematic view of a ship having a double shell structure.

FIG. 4 is a partially enlarged perspective view of a hull showing an example of a conventional wave load measuring device.

[Explanation of symbols]

 1 hull 2 outer shell 3 inner shell 4 transformer 5 longe 5a surface material 6 longe 8 laser light emitter 8a laser light 8b reflected light 9 laser light receiver 10 laser displacement meter 11 controller 12 recorder D. L hull draft line

Claims (1)

[Claims] 1. Among the longi of the outer shell in the double shell structure hull in which the outer shell and the inner shell reinforced by the longi are partitioned by a transformer, the central part of the longi near the waterline level of the hull. Then, a laser displacement meter consisting of a laser light emitter that emits laser light and a laser light receiver that detects the reflected light is installed between adjacent transformers,
And a controller having a controller for calculating a wave load acting on the outer shell based on the reflected light detected by the laser receiver, and a recorder for recording the calculated value by the controller. A wave load measuring device for ships characterized by: